Engagement is an inseparable part of the learning process and a multifold phenomenon. It has been categorized into different classifications: Behavioral engagement such as the effort; emotional engagement such as high levels of enthusiasm which is linked with low levels of anxiety and boredom; cognitive engagement such as the usage of learning strategy and self-regulation; agentic engagement such as the amount of conscious effort so that the learning experience would be enriched (Veiga et al., 2014; Hiver et al., 2021). Amongst the aforementioned categories, the one which is strongly important in the learning process is behavioral engagement in that it is relevant to the actual recognition of an individual's learning talents (Dörnyei, 2019).

Another possibility that can be viewed is to consider engagement from two other aspects, internal and external. The former implies how much time and effort is allocated to the process of the learning while the latter entails the measures that are taken at the institutional level so that the resources would be dealt with along with other options of learning and services for support which encourage the involvement in activities leading to the possible outcomes such as consistency and satisfaction (Harper and Quaye, 2009). Much attention is deserved to be paid to engagement since it is perceived as a behavioral means with which students' motivation can be realized and as a result, development through the learning process can occur (Jang et al., 2010). Active involvement should be strengthened in L2 classes to prevent disruptive behaviors and diminish the valence of emotions that are negative such as feeling anxious, frustrated, and bored.

It has been claimed by some writers (Skinner, 2016) that disengagement itself does not happen frequently in educational settings due largely to the fact that it is related to extreme behaviors, and it is when another phrase disaffection can be considered significant. Disaffection is characterized by disinterest, aversion, resignation, and reduced effort. Therefore, our perception of boredom as a complex emotion can be enhanced, and it can be dealt with more systematically if boredom is viewed through the following factors, disengagement, and disaffection (Derakhshan et al., 2021). In language learning context and use, engagement with learning a language is a cognitive, affective, and/or social process where the learner is viewed as the agent and language is regarded as the object. The learner is engaged:

As it has been believed both teachers' positive attributes and negative attributes can have an effect on students' engagement (Greenier et al., 2021). However, detrimental effects are the only impacts that are left when teachers feel apprehensive and solicitous. Irreparable damage is caused by teachers' apprehension since they cannot provide students with opportunities to express themselves and to reach their pinnacle with regard to the learning process. To be precise, a closer look can be taken through the items of teachers' apprehension scale and the way they impact students' engagement (Ghanizadeh et al., 2020). The first item which falls under the category of L2-related factors is: I am anxious when I have to deal with unfamiliar idioms or expressions in English; when the teacher himself could not leave his comfort zone and struggle to learn new words, how students are supposed not to be terrified by making mistakes and learning materials through trial and error. Item 26 of the STAS is: I feel anxious when words escape me. Forgetting and making mistakes are inseparable parts of learning a new language and they inevitably happen when one is making endeavors to learn a new language. When teachers feel so, students cannot have the bravery to show themselves and continue talking when they forget a word and they feel embarrassed, so as a consequence, they are less likely to be engaged in the activity. The third item which falls under the category of attitudinal factors is: I am not confident in speaking English. To speak a language, confidence needs to be built and it takes high self-esteem when one intends to start speaking a new language. Therefore, when teachers themselves are not confident enough to speak a new language, how their students can be encouraged to overcome language barriers and start speaking a new language without feeling shy and it undoubtedly causes a decrease in the amount they are willing to engage in the classroom activities. Item 25 which falls under the category of organizational factors in this scale is: When my students do not actively participate in class activities, I feel apprehensive. Students' not participating in the activities shows that there might be something wrong with teachers' teaching methods, teachers' stroke, teachers' credibility, teachers' care, teachers' immediacy or students' mental or physical health (Xie and Derakhshan, 2021). What aggravates the situation in this context is that the more apprehensive a teacher feel, the less engaged students are to take part in class activities. The last item of STAS, number 33 is: I feel anxious when I am not praised by the students. It has been told that a teacher should be intrinsically motivated so as not to need someone' s acclaim. When the teachers are required to be praised by their students to feel better about their jobs, students are not expected to rely on such teachers and be willing to engage in the class activities. The conclusion that can be drawn out of the above-mentioned points is that teachers' apprehension and students' classroom engagement are negatively correlated.