1. Introduction

With the advent of globalization and the increasing frequency of economic and cultural exchanges between nations, enhancing students' foreign language performance has become a critical priority for educators worldwide. This shift in focus emphasizes improving students' proficiency in foreign languages rather than merely elevating their test scores. In recent years, researchers started to pay more attention on understanding how Foreign language emotions, particularly within the framework of Positive Psychology, impact students' foreign language learning. Among all foreign language emotions, Foreign Language Enjoyment(FLE) has been regarded as a significant factor that positively affect the learning process and outcomes of students.

The burgeoning field of FLE has garnered considerable attention for its potential to enhance various aspects of language learning. Existing research highlights the beneficial influence of FLE on learning engagement, academic achievement, and language proficiency. This article aims to provide an overview of the effects of FLE on both the learning process and outcome. In this article, the primary research questions are: What is the effect of FLE on students in the foreign language learning process? How does FLE affect student's language learning outcomes? To answer these questions, a comprehensive review of existing literature will be conducted, analyzing studies that have employed various research methods, including qualitative, quantitative, and mixed-method approaches. By synthesizing existing research, this article provide valuable perspectives for educators and researchers in the domain of Second language acquisition(SLA). It suggests that in order to help achieve foreign language teaching goals more efficiently, language educators should focus on students' emotional factors and their complex impact on language learning and adjust teaching strategies to meet students' needs.

2. FLE: Theory and Definition

The investigation of FLE is intricately linked with the development of Positive Psychology, a field dedicated to the scientific exploration of positive human experiences to enhance individual well-being and quality of life. Positive Psychology posits that emotions such as joy and hope can significantly bolster learners' motivation and engagement, thereby improving language learning outcomes [1]. Empirical studies have demonstrated that positive emotions can alleviate anxiety, increase learners' confidence, and enhance overall language performance [2].

The conceptualization of FLE has evolved as research in this area has advanced. Dewaele and MacIntyre define FLE as an intricate emotional state, showing the joy and fulfillment in the process of foreign language learning [1]. They describe it as a sentiment that extends beyond mere classroom activities, permeating through interactions with classmates and educators, and deeply embedding itself within the learner's overall study experience. They also established the FLE Scale (FLES), later widely used as a standard scale to measure FLE. Jin and Zhang define FLE as the gratification and delight that stem from immersing oneself in the activities of foreign language learning [3]. They suggest that this pleasure not only enhances a learner's motivation but also bolsters their eagerness to communicate. Pishghadam et al. define FLE as a state of positive emotional experience that is stimulated by pleasurable and captivating language learning experiences [4]. They argue that this state is significantly shaped by the behaviors of educators and the ambiance of the learning environment.

These definitions underscore the importance of positive emotion factors in language learning. FLE is widely acknowledged as a motivational force that positively impacts language acquisition. However, the definitions vary in their focus. Some emphasize internal emotional experiences and their effects on motivation and communication, while others highlight the influence of the classroom environment and teaching methods. Collectively, these perspectives suggest that FLE should be understood as a multifaceted concept essential for effective language learning.

3. Empirical Studies on FLE in Second Language Learning

Numerous empirical studies have investigated the impact of FLE on foreign language performance in educational settings. These studies primarily focus on the effect of FLE on the learning process and its effect on learning outcomes.

3.1. The Effect of FLE on the Learning Process

In SLA, Learning engagement refers the active and committed involvement of learners during language learning process, encompassing both cognitive and emotional engagement, active interaction with peers and instructors, and a willingness to participate in classroom activities [5]. The level of student engagement serves as a strong indicator of the influence of FLE on the learning process.

Dewaele and Li focus on the impact of teachers' enthusiasm on students' foreign language emotions and social behavior learning engagement, especially in Chinese EFL classrooms. Using quantitative analysis and qualitative interviews, researchers investigated learners from 11 universities in China. The study found that FLE plays an intermediary role between teachers' enthusiasm and students' learning engagement [6]. This study provides a theoretical basis for emotional transmission in teaching practice.

Based on positive psychology and complex dynamic system theory, Yu et al. explore the diachronic development and dynamic interaction of FLE and learning engagement. A four-month follow-up study was conducted among 250 Chinese non-English majors. This study innovatively uses the growth mixture model to identify the development trajectory of FLE and learning engagement. The study found that in both the short term and the long-term learning process, FLE is supportive of the learning engagement of Chinese English learners [7].

Song and Wang conducted a four-month follow-up study among 682 Chinese non-English major college students. The study found that FLE appear as an intermediary factor between social support and learning engagement. This study provides empirical evidence to support the idea that FLE can significantly predict learning engagement [8]. It guides foreign language teachers to actively build an effective social support system, and cultivate students' learning pleasure to enhance learning engagement.

Research in this field is mainly carried out from two aspects. One is the direct correlation between FLE and learning engagement, and the other is the indirect influence of FLE as an intermediary factor on learning engagement and other phenomena. A synthesis of these studies reveals that FLE, as a form of positive emotion, has the potential to enhance students' interest and motivation, thereby leading to increased participation in learning activities and heightened learning engagement. FLE influences the language learning process through three main pathways. Firstly, FLE can reduce anxiety and increase confidence. When learners experience pleasure in foreign language learning, their levels of anxiety may decrease, and their self-confidence may increase. This reduction in anxiety and boost in confidence can enhance their active participation and engagement in learning activities. Secondly, FLE can promote cognitive and affective engagement. Students are more inclined to engage in deeper cognitive processing and positive affective experiences when they are in a pleasurable emotional state. This heightened engagement contributes to greater learning efficiency. Thirdly, FLE shows dynamic interaction and synergistic development. FLE and learning engagement do not exist in isolation but interact dynamically in the course of foreign language learning. FLE that students gain in one period may enhance their learning engagement in the following period, and vice versa, forming a positive cycle.

Besides, the studies also show that there are differences in the developmental trajectories of FLE and learning engagement among different students. Some students may start with high levels of FLE and engagement, and their FLE and engagement may decline over time, while others may start with low levels of FLE and engagement, but gradually grow over time. This heterogeneity highlights the necessity for educators to consider individual differences among students and to implement tailored teaching strategies aimed at fostering both FLE and learning engagement.

3.2. The Effect of FLE on Learning Outcome

Li and Han investigated using quantitative analysis and qualitative interviews with questionnaire survey to inspect the predictive influence of foreign language emotions on students' online learning outcomes. The research found that FLE can positively predict language test scores and have an optimistic effect on online learning achievement, while anxiety and boredom had negative effects [9]. Compared to studies in the same field, this study is innovative in that it focuses on learners' emotional experiences in online classroom environments. While most existing studies have focused on traditional classroom settings, this study fills the gap by probing the impact of foreign language emotions in online teaching and learning environments.

To investigate the mediating effect of FLE on critical thinking and foreign language achievement, Ma, Li, and Jiao conducted a survey of 4113 foreign language learners with path analysis based on rational-emotive theory. The study confirmed the importance of cultivating critical thinking and stimulating active emotions in students' language learning course, suggesting the need for further exploration of the mechanisms by which emotions influence language learning outcomes [10].

Under the guidance of Positive Psychology, Cui and Meng studied the correlation between self-efficacy, FLE, and English proficiency. Their research combined quantitative surveys and qualitative interviews with 276 non-English major college students. The results demonstrate that self-efficacy contributes actively to on English proficiency, with FLE serving as a mediator, highlighting the need for educational practices that enhance self-efficacy and positive emotions to improve language learning outcomes [11].

Tsang and Dewaele studied the emotions of anxiety, boredom, and FLE in young EFL learners, focusing on their impact on foreign language proficiency [12]. Using questionnaires and English tests completed by 111 Grade 3–4 children, the research employed various statistical analyses to investigate the interrelationships of these variables. Results showed that FLE was the strongest predictor of proficiency.

In the studies reviewed, the assessment of foreign language learning outcomes extended beyond traditional objective test scores to include students' subjective evaluations. This multifaceted approach facilitated a comprehensive assessment of learners' performance and their subjective experiences related to foreign language acquisition. By combining quantitative achievement data and qualitative self-assessment, the researchers were able to gain a more accurate understanding of the effect of FLE on foreign language learning outcomes.

The synthesis of these studies reveals that FLE influences students' learning outcomes through four primary pathways. Firstly, FLE directly contributes to learning outcomes. FLE serves as a significant positive predictor of foreign language achievement. When students find pleasure during the process of learning foreign, their result of language tests and assessments tends to improve. This direct effect underscores the role of positive emotional experiences in enhancing learners' ability to achieve higher scores in foreign language evaluations. Secondly, FLE can reduce anxiety and boredom. FLE is inversely related to levels of foreign language anxiety and boredom. Students who derive pleasure from learning a foreign language often experience lower levels of anxiety and boredom, which are commonly recognized as impediments to effective learning. By alleviating these negative emotions, FLE indirectly enhances learning effectiveness. The reduction in anxiety and boredom helps maintain learners' focus and improves their overall learning efficiency. Thirdly, FLE serves as a mediating role. In several studies, FLE functions as a mediating variable that links other psychological factors, such as self-efficacy, to foreign language achievement. For instance, learners with higher self-efficacy, who possess greater confidence in their abilities, have a higher possibility to gain more pleasure in learning. This heightened FLE, in turn, fosters greater engagement and contributes to improved academic performance. Thus, FLE plays a crucial mediating role in translating psychological attributes into tangible learning outcomes. Fourthly, FLE has an expansive and constructive effect on positive emotions. According to Positive Psychology theory, positive emotions like FLE expand individuals' cognitive and behavioral scopes and construct valuable resources, including cognitive, motivational, and social resources. These resources enable learners to maintain a positive attitude and enhance their problem-solving abilities throughout the learning process. For this reason, the constructive effects of positive emotions facilitate better foreign language learning outcomes by improving learners' resilience and adaptability.

The integration of objective and subjective measures of learning outcomes offered researcher and educators a chance to gain a more comprehensive judgement of FLE's impact on language learning outcomes. By examining the direct, indirect, mediating, and constructive roles of FLE, these studies highlight the multifaceted ways in which positive emotional experiences contribute to foreign language learning success.

4. Conclusion

In summary, FLE positively influences foreign language performance through various mechanisms. During the learning process, FLE contributes to enhanced learning engagement by building students' confidence, promoting cognitive and affective involvement, and fostering dynamic interactions at both individual and group levels. Regarding learning outcomes, FLE directly improves effectiveness, mitigates the impact of negative emotions, and acts as a mediating variable connecting other psychological factors to language performance.

The research on FLE mainly focuses on foreign language learners within educational settings, encompassing a range of demographics, including high school students, elementary pupils, and both English major and non-English major students. Regardless of age, FLE consistently aids learners in engaging more effectively in the foreign language learning process and achieving better learning outcomes.

Utilizing the FLE Scale (FLES) as a standard measurement tool, researchers have employed various methodologies in their empirical studies. The most prevalent method is the questionnaire survey, which collects data on different facets of students' learning experiences. Additionally, some studies have employed mixed-methods approach, combining quantitative data from surveys with qualitative insights from interviews to provide a more comprehensive and varied understanding of FLE's effects. A smaller number of studies have utilized longitudinal methods to track changes in FLE over the course of the learning course.

By offering reliable empirical evidence, these studies significantly advance the theoretical understanding of the significance of FLE and other foreign language emotions in language learning. The findings have practical implications for teaching practices, highlighting the necessity to stimulate students' positive emotions and manage negative ones to enhance the language learning experience. Insights gained from these studies can inform the development of interventions aimed at improving students' language learning outcomes.

It is recommended that researchers conduct further longitudinal studies to explore the standing impact of FLE on students' learning process as well as outcomes. Additionally, new teaching methodologies could be developed to enhance FLE, and an evaluation system could be established to assess the effectiveness of such methods. Further investigation into the application of artificial intelligence technologies in foreign language teaching is also suggested, with research focusing on how these technologies might affect students' FLE in learning process and overall learning outcomes.