Gamified Mobile Learning to Enhance Vocabulary Acquisition and Speaking Fluency among Secondary EFL Students

Introduction

Vocabulary acquisition and speaking fluency are central learning outcomes in secondary EFL education because learners need both lexical command and sustained oral delivery to participate in meaningful communication. Gamified approaches have gained substantial visibility in technology-enhanced language learning research, with studies highlighting their potential to stimulate sustained engagement, repeated participation, and deeper interaction with target language input (Erdiana et al., 2025; Ferdiansyah et al., 2025; Romsi et al., 2024). For English as a Foreign Language (EFL) learners, game elements such as quests, points, leaderboards, and time-bound challenges have been shown to heighten learners’ willingness to practice and increase the frequency of exposure to vocabulary and oral tasks, creating conditions that support lexical consolidation and speech automatization (Slamet et al., 2024b, 2024a; Slamet & Basthomi, 2024; Widodo et al., 2025). Despite these advantages, the literature also reveals that engagement fostered through gamification does not consistently translate into improved linguistic outcomes. Several investigations report that learners sometimes prioritize goal completion over meaningful linguistic processing, resulting in superficial participation that limits vocabulary retention and reduces the quality of oral output (Basthomi et al., 2025; Ikhwan et al., 2025; Slamet et al., 2025b, 2025a). These findings indicate a critical need to examine how game dynamics shape cognitive engagement and whether motivational features genuinely facilitate measurable gains in vocabulary and spoken fluency rather than merely increasing participation.

Parallel research on mobile-assisted vocabulary learning demonstrates that multimodal input, spaced repetition, and immediate feedback can strengthen receptive and productive lexical knowledge (Cancino & Viguera, 2024; Fithriani, 2021; Gao & Pan, 2023). However, many studies isolate vocabulary outcomes from oral performance, preventing a comprehensive understanding of how mobile learning supports the integration of lexical retrieval with real-time speech production for EFL learners (Afshar & Jamshidi, 2022; Farhane, 2025; Hanafiah et al., 2022). Evidence regarding spoken fluency is similarly fragmented. While mobile tasks have shown potential to improve speech rate and reduce hesitation in controlled contexts, several studies note inconsistent effects during spontaneous communication, suggesting that lexical learning does not automatically transfer to fluent connected speech (Alimorad & Saleki, 2022; Hanafiah et al., 2022; Yang et al., 2024). Furthermore, most research treats vocabulary and fluency as separate constructs, overlooking psycholinguistic perspectives that emphasize their interdependence during speech formulation. These limitations underscore the need for research that examines how gamified mobile tasks simultaneously influence vocabulary acquisition and spoken fluency, particularly through mechanisms that integrate retrieval practice, speech planning, and real-time oral performance for EFL learners.

Vocabulary acquisition demands precise operationalization that accounts for receptive recognition, productive retrieval, depth of semantic and collocational knowledge, and the ability to mobilize lexical items during spontaneous communication. Although scholars consistently highlight vocabulary as a foundational component of fluency development (Avila & Fonseca, 2021; Samortin, 2020), many studies continue to measure lexical gains through narrow indicators such as raw word counts or surface-level accuracy ratios, which overlook how learners internalize and manipulate vocabulary in real-time interactions in an EFL context. Spoken fluency, similarly, involves a multifaceted construct that integrates temporal features, pausing behavior, repair patterns, and the smooth orchestration of connected speech (Gao & Pan, 2023; Permata et al., 2024). Yet prior research often isolates individual features without examining how lexical access supports or constrains fluency processing. This narrow focus limits understanding of how mobile and gamified learning environments mediate the reciprocal relationship between vocabulary resources and fluent speech production, an intersection increasingly emphasized in psycholinguistic and technology-enhanced language learning research for EFL learners (Fan & Wang, 2025; Liu, 2024).

Taken together, gaps persist regarding the integrated effects of gamified mobile learning on both vocabulary acquisition and spoken fluency, the mechanisms by which game-based features shape linguistic performance, the specificity of construct operationalization, and the limited scope of prior measurements that overlook dynamic interactions between lexical retrieval and fluent speech. These gaps provide a rationale for examining how a structured gamified mobile learning intervention supports learners’ vocabulary growth and fluency development, and how learners navigate cognitive, motivational, and linguistic demands embedded in game-driven tasks.

Literature Review

Gamified Mobile Learning in Language Education

Gamified mobile learning has gained increasing attention as researchers seek to understand how digital platforms enriched with game mechanics can support sustained language development. In the EFL context, studies consistently emphasize that mobile applications provide portability, immediate feedback, multisensory input, and frequent interaction, all of which are conducive to language practice (Avila & Fonseca, 2021; Cancino & Viguera, 2024). When augmented with game elements such as levels, quests, reward systems, and performance challenges, these environments tend to heighten engagement and persistence (Fan & Wang, 2025; Hanafiah et al., 2022). However, the literature indicates that elevated engagement does not automatically translate into deeper language learning outcomes. Several studies report that learners may focus on point accumulation rather than cognitive investment, resulting in superficial participation and inconsistent transfer of language skills to real communicative contexts (Fithriani, 2021; Liu, 2024; Slamet & Basthomi, 2024). In addition, research often isolates engagement and motivation as endpoints without explaining how game dynamics facilitate specific linguistic processes. These gaps highlight the need to further examine the mechanisms through which gamified mobile features influence measurable language skills, particularly when tasks demand lexical retrieval and performance under time constraints for EFL learners. Evidence on multimedia games also indicates that game-supported learning may strengthen affective engagement when interest and motivation are explicitly designed into the task cycle (Ghanbaran et al., 2015).

Vocabulary Acquisition in Digital and Gamified Environments

Vocabulary acquisition remains central to second language proficiency, yet studies using digital tools frequently emphasize breadth over depth of word knowledge. Research shows that mobile learning platforms can strengthen recognition and recall through spaced repetition, audiovisual cues, and contextualized microlearning (Cancino & Viguera, 2024; Gao & Pan, 2023). In the EFL context, gamified vocabulary activities, including timed quizzes and badge-awarded mastery cycles, can reinforce repetition and encourage learners to revisit challenging items (Avila & Fonseca, 2021; Cancino & Viguera, 2024). Despite these advantages, existing studies tend to operationalize vocabulary growth using limited metrics that overlook nuanced dimensions such as collocational accuracy, form-meaning connections, and productive retrieval in real-time speaking. Furthermore, the literature seldom investigates how vocabulary gains achieved within gamified systems translate to spontaneous or semi-spontaneous oral communication (Fithriani, 2021; Permata et al., 2024; Samortin, 2020). Such gaps indicate that vocabulary learning should be examined as both a cognitive and performance-based construct to capture a more complete picture of learners’ lexical development within gamified mobile EFL contexts. Ghanbaran and Ketabi (2014) further emphasize that multimedia games can support vocabulary learning through both incidental exposure and intentional lexical practice, which aligns with the present study’s integration of recognition, recall, and speaking-based retrieval.

Speaking Fluency Development in Technology-Mediated Learning

Speaking fluency research increasingly acknowledges the multifaceted nature of fluent performance, involving speed, pause management, repair patterns, and connected speech features (Elverici, 2023; Gkomptzia, 2024). Technology-mediated tools, including mobile applications and voice-based tasks, have been found to create low-pressure environments that encourage rehearsal and repeated attempts, potentially strengthening fluency through iterative production (Köroğlu, 2021; Mohzana, 2024). Gamified speaking tasks, such as timed missions or performance streaks, may further stimulate learners to produce speech under conditions that approximate real communicative demands (Pituxcoosuvarn et al., 2024; Wong & Yunus, 2023; Yang et al., 2024). However, in the EFL context, the literature notes mixed outcomes. Some learners achieve smoother delivery with reduced hesitations, while others exhibit task-induced stress, uneven pacing, or overly memorized performances that do not necessarily reflect authentic fluency (Yin & Chen, 2024). Existing studies often emphasize frequency of speaking practice rather than analyzing how gamified constraints shape cognitive load, real-time monitoring, and long-term fluency shaping. These inconsistencies suggest the need for research that explores how speaking fluency develops when mobile platforms incorporate both motivational and performance-driven mechanics for EFL learners.

Theoretical Framework and the Study Context

This study is grounded in usage-based gamification (Landers, 2014) and socioconstructivist perspectives (Foo & Hussain, 2010), which view language development as emerging through repeated meaningful encounters with input, frequent retrieval of linguistic forms, and authentic communicative use supported by interactional demands and contextual cues. Gamified mobile learning operates as an enabling environment where cognitive engagement, emotional investment, and behavioral participation converge to facilitate vocabulary consolidation and fluent oral production. Within this framework, the study was situated in a private secondary school in East Java, Indonesia, a context characterized by diverse learner proficiency levels, varied digital experiences, and a curriculum that prioritizes communicative competence. The school’s reliable access to mobile devices, structured English instruction, and administrative encouragement for technology-aided learning created optimal conditions for examining how gamified tasks function across heterogeneous learner profiles. These contextual features allow the findings to offer meaningful insights for comparable EFL institutions seeking to strengthen vocabulary development and enhance spoken fluency through structured mobile-based gamified activities that integrate repeated exposure, retrieval practice, and real-time oral performance.

This study is guided by the following two research questions (RQs):

1. How does gamified mobile learning influence learners’ vocabulary acquisition as reflected in receptive and productive lexical performance?
2. How does gamified mobile learning affect learners’ spoken fluency as demonstrated through temporal, performance, and delivery features of connected speech?

Methodology

Research Design and the Participants

This study utilized a quasi-experimental pretest–posttest design to investigate how a systematically structured gamified mobile learning intervention shaped students’ vocabulary acquisition and spoken fluency, allowing for the examination of changes in both receptive and productive lexical abilities as well as temporal, performance-based, and delivery-related features of connected speech. Because the school’s administrative regulations prevented random redistribution of learners, intact classes were selected; however, to reduce potential systematic differences commonly associated with non-random grouping, classes were carefully chosen based on comparable English proficiency profiles drawn from placement test scores and prior semester achievements. Further controls were implemented by ensuring that both groups received identical instructional hours, comparable teacher qualifications, and equal access to supplementary learning materials, thereby minimizing instructional and environmental discrepancies that could influence outcomes.

The sample consisted of 122 Grade 8 students who fulfilled three inclusion criteria designed to maintain data reliability (Bouncken et al., 2025): consistent attendance, access to a mobile device compatible with the gamified platform, and full participation across all intervention components. Students presenting diagnosed speech disorders or experiencing extended absences were excluded to safeguard interpretive consistency across fluency and lexical measures. Demographic information was gathered to characterize participant backgrounds and account for variability related to age, gender, device usage patterns, and prior exposure to English learning, enabling a more controlled interpretation of observed changes in vocabulary development and fluency performance.

Table 1. Participant Demographics (n = 122)

Instruments

The study utilized four primary instruments. First, the receptive and productive vocabulary test was adapted from validated lexical assessment frameworks and included multiple item formats measuring recognition, controlled production, and free recall. Content validity was ensured through expert review by two language assessment specialists who evaluated item relevance, difficulty estimation, and alignment with target learning outcomes. A pilot administration involving students outside the main sample (n = 28) provided reliability coefficients, resulting in Cronbach’s alpha values of 0.87 for receptive and 0.84 for productive components. Second, the rubric-based speaking fluency assessment measured speech rate, pauses, repairs, and smoothness of delivery during a two-minute monologue task. The rubric underwent interrater reliability testing, with two trained raters achieving a Cohen’s kappa of 0.81 after calibration sessions using benchmark recordings.

The third instrument, a closed-ended questionnaire adapted from Basthomi et al. (2025) and Slamet and Basthomi (2024), captured learner engagement patterns, perceived cognitive demands, and interaction with gamified tasks. Its construct validity was verified through exploratory factor analysis during piloting, and internal consistency reached an alpha of 0.89. Finally, structured interviews were conducted with 12 purposively selected participants representing high, mid, and low performers on the posttest to explore varied experiences. To reduce potential interviewer bias, a semi-structured protocol was used, interviewer neutrality training was provided, and interviews were audio-recorded and transcribed verbatim. Triangulation with questionnaire data and performance outcomes further strengthened the credibility of insights generated from the interviews.

Data Collection Procedures

Data collection was conducted over eight weeks following a systematic sequence designed to capture measurable changes in vocabulary acquisition, speaking fluency, and learner engagement with the gamified mobile intervention. In Week 1, administrative permissions were obtained, informed consent was secured from all participants, and students completed a detailed demographic and learning profile questionnaire. Week 2 involved administering the receptive and productive vocabulary pretests and the baseline speaking fluency assessment under standardized, proctored conditions to ensure score validity and reliability. The intervention began in Week 3 with the introduction of the gamified mobile platform, during which students received a structured orientation covering system features, navigation procedures, task objectives, and expectations for timely completion. To reduce procedural bias, all instructions were fully scripted, displayed through identical demonstrations, and delivered simultaneously across intact classes. The pretest was administered before any platform orientation, while the posttest used the same vocabulary-test structure and parallel speaking prompts after the final intervention week under identical proctored conditions.

The intervention incorporated three central gamified components that aligned with the weekly instructional objectives and curricular themes. Progress quests targeted incremental vocabulary expansion through scaffolded lexical tasks. Time-bound speaking missions facilitated repeated fluency practice by prompting learners to produce short oral responses within controlled time frames. Reward-based vocabulary cycles reinforced retrieval through cumulative challenges that encouraged spaced practice. These components were integrated with classroom instruction on topics such as daily activities, school routines, descriptive expressions, and short narrative production. Learners engaged with the mobile tasks both during lessons and independently outside class, allowing for flexible yet structured participation.

Throughout the intervention period, teachers monitored weekly completion logs generated automatically by the platform to maintain participation consistency and identify learners requiring additional support. In Week 8, semi-structured interviews were conducted to explore learner experiences, perceptions of difficulty, motivational shifts, and perceived learning gains. Participants were selected across high, mid, and low performance tiers to ensure diverse representation. To reduce interviewer influence, neutral probing strategies were employed, and triangulation across platform analytics, questionnaire responses, vocabulary and fluency performance data, and interview narratives enhanced the credibility and dependability of the overall findings.

Table 2. Weekly Intervention Structure

Data Analysis

The quantitative analysis incorporated a multi-layered procedure to capture changes in learners’ vocabulary acquisition and spoken fluency with precision. Normality was checked using the Shapiro-Wilk test; scores from receptive and productive vocabulary tests were examined using paired samples t tests, with Wilcoxon signed-rank tests reserved for any non-normal indicators to determine the statistical significance of pretest–posttest differences, complemented by Cohen’s d to assess the magnitude of improvement beyond raw score comparisons. Speaking performance was processed through detailed audio transcription, after which fluency indicators such as speech rate, articulation time, pause duration, filled and unfilled pauses, and repair behaviors were coded using a standardized rubric adapted from established fluency measurement frameworks to ensure consistency across samples. Questionnaire data were analyzed through both descriptive statistics and inferential examination of factor-aligned subscales to capture variations in engagement, cognitive demand, and task interaction. Qualitative interview data were subjected to a rigorous thematic analysis beginning with open coding, followed by axial and selective coding to refine category relationships and ensure conceptual clarity. To strengthen reliability, multiple coders conducted independent analyses and resolved discrepancies through negotiated consensus supported by codebook calibration (Braun & Clarke, 2006, 2025). Triangulation across quantitative outcomes, self-report measures, and qualitative insights enabled the construction of a multidimensional interpretation of learners’ responses to the gamified intervention, thereby enhancing analytic credibility and validating observed patterns across complementary data sources.

Ethical Considerations

Ethical procedures followed institutional standards and prioritized participant welfare and fairness. Approval was secured from the IRB of STAI Diponegoro Tulungagung
(No. 5.6.18/EC-DIPTA/PL/2025). Informed consent and assent were obtained, and anonymity was ensured through coded identifiers and secure, restricted data storage. Participation held no academic consequences, and students could withdraw freely. Standardized testing procedures, uniform instructions, neutral interviewer conduct, and multiple independent raters for speaking assessments were used to reduce bias. Reflexive memos documented the researcher’s assumptions throughout the analysis. To maintain equitable access, temporary device support was provided for students who lacked functional mobile phones, ensuring consistent engagement with the intervention.

Results

RQ 1: How does gamified mobile learning influence learners’ vocabulary acquisition as reflected in receptive and productive lexical performance?

To address RQ1, the study examined the impact of the gamified mobile learning intervention on students’ vocabulary acquisition, focusing on three dimensions: recognition, controlled production, and free recall. Data were collected using pre- and post-tests of receptive and productive vocabulary to capture changes in both understanding and active use of target lexical items. The analysis considered not only mean score improvements but also effect sizes and statistical significance to evaluate the magnitude and reliability of observed changes. The following table presents a detailed comparison of pretest and posttest outcomes.

Table 3. Pretest and Posttest Vocabulary Scores (n = 122)

The analysis indicates that students demonstrated substantial improvements across all three dimensions of vocabulary acquisition. Recognition scores increased by an average of 14.09 points, reflecting a heightened ability to identify target words when presented in written or visual contexts. Controlled production also showed meaningful growth, with learners more accurately retrieving and producing words in structured sentence frames, suggesting improved mapping between form and meaning. Free recall, often considered the most challenging measure of productive vocabulary, revealed significant gains of 13.73 points, highlighting that students were increasingly able to spontaneously retrieve and apply lexical items in unscripted contexts.

Cohen’s d values indicate very large effect sizes across the three measures, suggesting that the gamified intervention produced not only statistically significant improvements but also meaningful pedagogical impact. Recognition showed the largest effect size (d = 1.61), likely reflecting the cumulative reinforcement through repeated quests and visual cues embedded in the gamified platform. Controlled production and free recall exhibited slightly smaller but still robust effect sizes (d = 1.49 and d = 1.38, respectively), indicating that while learners effectively internalized vocabulary, additional scaffolding may be necessary to fully consolidate spontaneous usage.

In sum, the findings suggest that the gamified mobile learning intervention fostered substantial enhancement in learners’ vocabulary acquisition, demonstrating that structured, interactive, and motivationally rich tasks can facilitate both recognition and productive use of lexical items. The data indicate that repeated engagement with progress quests, reward cycles, and controlled production exercises not only strengthened learners’ ability to identify and recall words but also encouraged cognitive strategies for spontaneous retrieval. Moreover, the varied outcomes across recognition, controlled production, and free recall highlight the layered nature of vocabulary learning, suggesting that some learners consolidate receptive knowledge more rapidly than productive usage, while others benefit from the integrative scaffolding provided by gamified sequences. These insights underscore the importance of balancing task design to support durable lexical retention, scaffolded retrieval, and autonomous application in diverse communicative contexts, indicating that gamified mobile learning can serve as both a motivating and cognitively demanding platform for comprehensive vocabulary development.

RQ 2: How does gamified mobile learning affect learners’ spoken fluency as demonstrated through temporal, performance, and delivery features of connected speech?

To address RQ2, the study examined learners’ spoken fluency development in relation to gamified mobile learning through both self-reported engagement and qualitative insights. The closed-ended questionnaire captured engagement patterns, perceived cognitive demands, and interaction with gamified tasks across 20 items using a 5-point Likert scale. The items focused on learners’ perceptions of task difficulty, motivation, participation frequency, confidence in speaking, and use of vocabulary during speaking missions. The results are presented in Tables 4 through 6 according to three dimensions: engagement, cognitive demand, and task interaction, to provide a detailed understanding of how gamified features influenced learners’ spoken fluency experiences.

Table 4. Engagement Dimension of Learner Experiences (n = 122)

Note: SD = Strongly Disagree, D = Disagree, N = Neutral, A = Agree, SA = Strongly Agree, f = frequency

The engagement results indicate consistently strong involvement in the speaking missions, with high proportions of agreement across all items. Enjoyment of speaking missions reached 82.79 % agreement or strong agreement, reflected in a mean of 4.08 and a narrow standard deviation of 0.78, showing that learners responded similarly. Timely completion of missions showed comparable outcomes, with 82.79 % in agreement categories and a mean of 4.02, suggesting that the structured pacing supported task commitment. Motivation to improve speaking reached the highest mean of 4.11, supported by 87.71 % agreement, indicating that the gamified format stimulated sustained effort. Regular participation and peer collaboration also reflected stable engagement, with means of 4.05 and 4.00. The low percentages in disagreement categories, ranging only from 4.10 % to 8.20 % across items, suggest minimal resistance to task demands. Standard deviations between 0.76 and 0.82 further demonstrate consistency in responses. Overall, these results indicate that learners embraced frequent interaction, timely task completion, and collaborative processes, reinforcing the potential of gamified mobile environments to maintain continuous involvement necessary for developing fluent spoken performance.

Table 5. Cognitive Demand Dimension of Learner Experiences (n = 122)

The cognitive demand dimension reflects consistently high engagement, with all items yielding mean scores between 4.03 and 4.09 and relatively low standard deviations ranging from 0.74 to 0.79. These values indicate a stable collective perception that the speaking missions required sustained mental effort while remaining within manageable limits. For instance, 83.61 % of respondents agreed or strongly agreed that the missions were challenging but manageable (M = 4.07), and 82.79 % reported maintaining full concentration during tasks (M = 4.09). Similarly, over 83 percent indicated frequent use of vocabulary-retrieval strategies (M = 4.03), and 84.43 % experienced demands for quick speech production (M = 4.03). Minimal endorsement of disagreement options, consistently below 6 % across items, suggests that few learners experienced undue cognitive strain. Collectively, these patterns imply that the gamified speaking environment fostered an optimal level of mental activation that supported attention, lexical access, and rapid language formulation without imposing excessive cognitive burden.

Table 6. Task Interaction Dimension of Learner Experiences (n = 122)

The task interaction dimension reveals consistently strong engagement with the platform’s communicative features, supported by mean scores ranging from 3.99 to 4.11 and standard deviations between 0.75 and 0.82. A total of 84.43 % of learners reported responding immediately to prompts (M = 4.06), indicating that real-time interaction demands were manageable for most participants. Similarly, 83.61 % applied new vocabulary during speaking tasks (M = 4.07), reflecting active lexical integration. Monitoring of speech was also widespread, with 83.61 % selecting agreement options (M = 4.04). Enjoyment of competitive missions showed slightly more variability, with 79.51 % agreeing or strongly agreeing (M = 3.99; SD = 0.82), suggesting that competitive features may resonate differently across learners. Confidence in using vocabulary reached the highest endorsement, with 86.07 % agreeing (M = 4.11). Collectively, these results indicate that gamified speaking missions supported immediate task responsiveness, self-regulation, and confident lexical use, creating interactional conditions that encouraged sustained oral participation and facilitated continuous fluency-oriented practice.

Overall, the questionnaire results indicate that the gamified mobile learning intervention created a multifaceted environment that supported sustained engagement, cognitive focus, and strategic interaction during speaking tasks. Learners consistently reported high levels of participation, motivation, and confidence, demonstrating that repeated exposure to timed missions and reward-based vocabulary cycles encouraged active involvement and attentive monitoring of their own performance. The alignment between task challenge and cognitive capacity appears to have facilitated deliberate practice, allowing students to plan, retrieve, and apply vocabulary under conditions that approximated authentic communicative pressure. These findings suggest that gamified mobile learning not only promotes frequent oral production but also scaffolds cognitive strategies, enhances self-regulation, and strengthens the integration of lexical knowledge into fluent, connected speech, providing a robust platform for complex skill development over sustained instructional periods.

Semi-Structured Interview Findings

To complement the questionnaire data and gain a deeper understanding of learners’ experiences with gamified mobile learning, semi-structured interviews were conducted with 12 purposively selected participants representing varied performance levels and institutional backgrounds. The interviews focused on exploring learners’ perceptions of engagement, challenges, strategies, and vocabulary application during speaking missions. The data were coded thematically, and representative quotes from all participants (S1–S12) were included to provide a rich and nuanced understanding of task experiences.

Theme 1: Engagement and Motivation

This theme captures learners’ experiences regarding their level of interest, enthusiasm, and motivation while interacting with the gamified mobile platform. The interview questions guiding this theme included: How did you feel when participating in the speaking missions? What aspects of the tasks encouraged you to continue practicing?

Table 7. Engagement and Motivation

The engagement and motivation theme reflects a multifaceted interaction between personal enjoyment, sustained effort, and socially driven encouragement. Learners frequently described authentic satisfaction derived from completing missions, as illustrated by S1, who viewed each quest as an achievable challenge, and S3 and S5, who emphasized the gratification of monitoring daily progress and observing steady score improvements. Enjoyment was also tied to self-competition, with S7 highlighting the appeal of timed missions that demanded focused effort. Commitment emerged strongly, as S2 and S10 explained that they persisted through demanding tasks, while S6 noted that reward features heightened concentration, and S12 described continuing to speak despite errors. Social dynamics further reinforced motivation; S4 and S8 reported that comparing scores and streaks inspired additional effort, S9 appreciated collaborative group missions, and S11 felt encouraged by peer recognition. These insights indicate that the combination of playful elements, structured reinforcement, and peer interaction generated a motivational environment that supported continuous participation and gradually strengthened learners’ willingness to engage in oral tasks.

Theme 2: Cognitive Strategies and Task Management

This theme explores how learners approached speaking missions cognitively, including strategies for vocabulary recall, speech planning, and pacing. Interview questions included: What strategies did you use to remember words during missions? How did you manage speaking under time constraints?

Table 8. Cognitive Strategies and Task Management Coding and Quotes

The cognitive strategies and task management theme demonstrates that learners employed deliberate and varied mental processes to meet the linguistic and temporal demands of the gamified speaking missions. Vocabulary retrieval was supported through individual techniques such as S1’s sentence-based mental visualization, S2’s silent rehearsal for memory reinforcement, S5’s reliance on image–word associations provided in the app, and S8’s effort to activate previously learned items before responding. Time management also played a crucial role, with S4 increasing speech pace under pressure, S7 intentionally regulating pauses, S10 mentally tracking time to maintain message completeness, and S12 segmenting sentences to maintain smooth delivery within limits. Self-monitoring was equally prominent, as shown by S3’s immediate error correction, S6’s attention to pronunciation even during rapid speech, S9’s real-time evaluation of lexical accuracy, and S11’s brief adjustments to amend errors while sustaining coherence. These combined practices illustrate an environment that fostered autonomous regulation, strategic problem solving, and ongoing refinement of connected speech.

Theme 3: Vocabulary Application and Transfer

This theme examines learners’ perceptions of how effectively they were able to use newly learned vocabulary during speaking missions and beyond. The guiding interview questions included: How did you use the vocabulary from the tasks in your speech? Can you apply it in conversations outside the app?

Table 9. Vocabulary Application and Transfer Coding and Quotes

The vocabulary application and transfer theme highlights that learners actively integrated newly learned lexical items into both mission-based and real-life communication. Within the platform, S1 intentionally incorporated all recently learned words into complete sentences, S4 expanded responses by adding additional lexical items, S7 retrieved vocabulary from previous quests during spontaneous speaking, and S12 continued to use new words even when experiencing nervousness. Beyond the platform, S3 applied vocabulary in casual peer interactions, S6 deliberately integrated mission-related words into everyday conversations, S8 transferred lexical knowledge into short written paragraphs, and S11 recalled the target vocabulary during classroom presentations. Confidence-building was also evident, with S2 reporting greater assurance due to lexical familiarity, S5 experiencing reduced hesitation when mistakes occurred, S9 speaking more fluidly as recall became easier, and S10 feeling comfortable experimenting with novel expressions. Collectively, these insights demonstrate that repeated practice and purposeful task design supported active deployment, cross-context transfer, and strengthened self-belief in communicative ability, contributing to more autonomous and fluent language use.

Overall, the interview findings indicate that the gamified mobile learning intervention created a dynamic and supportive environment that fostered sustained engagement, strategic cognitive processing, and meaningful vocabulary application. Learners actively employed diverse strategies to recall and integrate lexical items while managing speech timing and self-monitoring their performance. The repeated practice embedded in quests and time-bound missions encouraged persistence, enhanced confidence, and promoted autonomous problem-solving in oral production. Participants also demonstrated the ability to transfer vocabulary knowledge to broader communicative contexts, indicating that the intervention supported both immediate task performance and durable language use. These insights suggest that gamified mobile learning can serve as an effective platform for cultivating metacognitive skills, linguistic competence, and adaptive strategies essential for developing fluent, contextually relevant oral communication.

The confirmation of results for RQ1 and RQ2 demonstrates that the gamified mobile learning intervention significantly enhanced learners’ vocabulary acquisition and spoken fluency, while also revealing areas that require careful pedagogical attention. For vocabulary, learners exhibited substantial gains in recognition, controlled production, and free recall, indicating that structured quests, reward cycles, and repeated retrieval effectively strengthened both receptive and productive lexical knowledge. At the same time, some learners displayed uneven pacing in free recall, suggesting that additional scaffolding may be necessary to support consistent spontaneous deployment. Regarding spoken fluency, participants reported high engagement, strategic self-monitoring, and effective application of vocabulary in timed missions, yet a few experienced cognitive load fluctuations when managing rapid responses under time constraints. These insights indicate that gamified mobile learning can reinforce linguistic performance and cognitive regulation, while future directions should focus on optimizing task sequencing, balancing challenge and support, and integrating reflective strategies to consolidate vocabulary and fluency development in authentic communicative contexts.

Discussion

The present study examines how gamified mobile learning can influence both vocabulary acquisition and spoken fluency among secondary EFL students, with attention to vocabulary, fluency, and learner response patterns. The findings indicate that integrating progress quests, timed speaking missions, and reward-based vocabulary tasks can facilitate notable improvements in learners’ lexical recognition, controlled production, and spontaneous retrieval. These outcomes align with prior research emphasizing that mobile-assisted language learning promotes vocabulary retention through repeated exposure, contextualized practice, and multisensory input (Fithriani, 2021; Yang et al., 2024). At the same time, the present study deepens this understanding by demonstrating that the combination of gamified features, structured feedback, and progressive difficulty not only strengthens cognitive mapping of lexical items but also fosters strategic planning and self-monitoring, addressing gaps noted in earlier studies where gamified interventions often prioritized engagement over measurable linguistic outcomes (Liu, 2024; Permata et al., 2024; Samortin, 2020). This synthesis suggests that carefully designed gamification can transform vocabulary learning from a passive recognition task into a dynamic, cognitively demanding process that cultivates both retention and productive deployment.

The results further indicate that spoken fluency benefits from the gamified mobile learning environment, particularly through repeated oral practice within time-bound missions and structured speaking tasks. The present findings extend previous evidence that technology-mediated language activities can lower affective barriers and provide opportunities for iterative rehearsal (Hanafiah et al., 2022; Permata et al., 2024) by showing that gamified missions simultaneously stimulate motivation, promote attention management, and encourage strategic speech planning. The alignment between cognitive demand and task pacing observed in this study addresses critiques in prior research that fluency improvements were inconsistent when learners experienced either insufficient challenge or excessive cognitive load (Erdiana et al., 2025; Ikhwan et al., 2025; Slamet et al., 2024a). By embedding reward systems and progressive task complexity, learners engaged in metacognitive monitoring, adjusting their speech rate, managing pauses, and deploying newly acquired vocabulary, demonstrating that gamification can scaffold the development of temporal, performance, and delivery aspects of connected speech while sustaining motivation over time. This suggests that gamified mobile learning functions not only as a motivational tool but also as a mechanism for cultivating self-regulated language learning behaviors essential for fluent oral production.

The interaction between vocabulary acquisition and spoken fluency observed in this study underscores the interdependent nature of lexical knowledge and oral performance. While previous studies often examined vocabulary and speaking as separate outcomes (Avila & Fonseca, 2021; Cancino & Viguera, 2024), the current findings indicate that repeated retrieval through gamified missions facilitates not only recognition and production but also smooth integration into connected speech. Learners’ ability to transfer vocabulary knowledge into timed speaking tasks highlights the importance of aligning task design with authentic language use, supporting the idea that fluency emerges from both cognitive consolidation and repeated practice in communicative contexts (Avila & Fonseca, 2021; Farhane, 2025; Gao & Pan, 2023). Furthermore, the study reveals nuances in learner responses, where some participants exhibited uneven pacing or task fatigue, emphasizing that even highly engaging gamified environments require careful scaffolding and differentiated support to maximize learning outcomes. These observations contribute to theoretical discussions about cognitive load management, metacognition, and the role of motivation in complex language tasks.

Additionally, the study’s findings advance the understanding of gamified mobile learning in EFL contexts by emphasizing the necessity of task integration, systematic progression, and reflective opportunities. While previous research highlighted engagement or immediate performance gains (Fan & Wang, 2025; Yang et al., 2024), the present study suggests that durable language development depends on designing tasks that simultaneously challenge learners cognitively, reinforce lexical retrieval, and promote self-monitoring. The triangulation of vocabulary assessments, speaking fluency measures, and qualitative learner insights provides a comprehensive perspective on how gamified tasks can influence both knowledge and performance, revealing the importance of balancing motivation, cognitive demand, and opportunity for transfer in pedagogical design (Fithriani, 2021; Liu, 2024).

In sum, the study demonstrates that gamified mobile learning can significantly enhance vocabulary acquisition and spoken fluency among secondary EFL learners when tasks are intentionally designed to incorporate progressive difficulty, cognitive scaffolding, and systematic retrieval practice. The results indicate that learners benefit not only from repeated exposure to target vocabulary but also from the structured opportunities to produce spoken language under time-bound and goal-oriented conditions, which promote automaticity, lexical accessibility, and sustained engagement. The interplay of motivational elements such as rewards and progress tracking with cognitive processes such as spaced practice, retrieval cycles, and task-based output contributes to deeper learning and more consistent performance gains. These outcomes underscore the pedagogical potential of gamification to cultivate meaningful, sustained language learning experiences that extend beyond traditional classroom practices. The findings further point to the need for future research to examine long-term retention trajectories, the effects of adaptive and personalized task sequencing, and the role of differentiated support mechanisms to maximize the effectiveness of gamified interventions across learners with varied proficiency levels, motivation profiles, and digital familiarity.

Conclusion

The findings of this study collectively demonstrate that gamified mobile learning offers a robust platform for enhancing both vocabulary acquisition and spoken fluency among secondary EFL learners, providing sustained engagement, cognitive stimulation, and opportunities for strategic language use. The integration of progress quests, time-bound speaking missions, and reward-based vocabulary tasks facilitated repeated exposure, retrieval practice, and active application of lexical items, enabling learners to consolidate recognition, controlled production, and spontaneous recall while also improving temporal, performance, and delivery features of connected speech. However, variations in learner responses, such as uneven pacing, task fatigue, and occasional cognitive overload, indicate that even highly structured gamified environments require careful scaffolding, differentiated support, and attention to individual learner needs to maximize outcomes. These insights have important pedagogical implications, highlighting the potential of gamified mobile learning to foster autonomous, self-regulated learning behaviors, enhance vocabulary integration into functional communication, and promote confidence in oral production. Limitations of the study include its reliance on a single school context, a relatively short intervention period, and potential self-reporting bias in qualitative data. Future research should examine long-term retention, adaptive task sequencing, cross-cultural generalizability, and the integration of reflective mechanisms to further optimize gamified interventions for diverse EFL populations.

Acknowledgements

The authors express their deep appreciation to all participating students whose contributions were essential to the completion of this study. Appreciation is also extended to the editor and anonymous reviewers for their valuable insights and constructive recommendations. This research was conducted independently and did not receive external funding support.

Declaration of Conflicting Interests

The authors declare that there are no conflicts of interest associated with this study.

APPENDICES

Appendix A. Vocabulary Test Blueprint and Sample Items

A1. Construct definition. The vocabulary test measured two complementary dimensions of lexical development: receptive vocabulary knowledge, defined as recognition of form-meaning relationships in contextualized input, and productive vocabulary knowledge, defined as the ability to retrieve and use target words accurately in controlled and semi-controlled contexts.

A2. Administration. The same test framework was administered as pretest and posttest under proctored classroom conditions. Equivalent item order and standardized instructions were used to minimize administration variance. Students were not permitted to use dictionaries, online translators, peer assistance, or platform hints during testing.

A3. Test blueprint by learning theme.

A4. Sample receptive vocabulary items. These sample items illustrate the item format and construct coverage. They are not reproduced as the full operational test to preserve test security.

1. Choose the best meaning: “The classroom was crowded.”
2. empty B. full of people C. very cold D. very quiet

Correct answer: B

2. Match the word with its meaning: “borrow.”
3. take and return later B. explain clearly C. arrive late D. write quickly

Correct answer: A

3. Complete the sentence: “After school, Rani went to the library to ____ a book.”
4. borrow B. crowded C. subject D. suddenly

Correct answer: A

A5. Sample productive vocabulary items.

1. Complete the sentence with an appropriate word: “I always ____ my homework before dinner.”

Expected answer examples: finish / complete / do. Score 2 for accurate meaning and form; score 1 for partially appropriate meaning; score 0 for incorrect or blank.

2. Use the word “helpful” in one meaningful sentence.

Score 2 for a grammatically acceptable and contextually appropriate sentence; score 1 for meaningful but structurally weak use; score 0 for incorrect meaning or no response.

3. Write one sentence about your school routine using the word “schedule.”

Score 2 when the word is used accurately in a school-routine context; score 1 for partial accuracy; score 0 for incorrect use.

Appendix B. Speaking Fluency Assessment Protocol and Rubric

B1. Task format. Students completed a two-minute monologue task before and after the intervention. They were given a familiar topic prompt, one minute of silent planning time, and two minutes of uninterrupted speaking time. The task was designed to elicit connected speech rather than isolated sentence production.

B2. Administration script. “You will speak for two minutes about the topic given by your teacher. You may think quietly for one minute before speaking. Do not read from a written text. Try to speak continuously, use the vocabulary you know, and complete your ideas clearly.”

B3. Sample speaking prompts.

1. Describe your daily activities from morning until evening.
2. Talk about your school day and the subjects you like.
3. Describe a place in your school and explain why it is important.
4. Tell a short story about an enjoyable learning experience.