The Effects of Cooperative versus Competitive Word Games on EFL Learners` Vocabulary Gain, Motivation, and Class Atmosphere

English vocabulary is considered difficult to learn and use in real life situations by most Iranian learners. In addition, many of them feel bored in vocabulary classes since they do not have the opportunity to take part in learning process, therefore, they lack necessary motivation to be pushed forward. Besides, they have not changed their learning habits, such as writing words on paper, trying to learn by heart or learning passively through teachers ` explanations. The reason must be that the main techniques used to practice in memorization while the features like fun, motivation and effort are ignored in almost all English classes. To help learners find language classes, especially vocabulary lessons more interesting, and to achieve more, the researcher used word games, which are generally engaged as a source of entertainment to serve an educational purpose, as instructional tools in practicing newly taught words. Moreover, the researcher compared the effects of two types of word games (cooperative versus competitive) on learners ` motivation, attitudes toward their teacher, class atmosphere, and vocabulary achievement, in order to investigate which game type was more successful in this field. In order to achieve this goal, this study has been done on 60 male English learners with the age range of 17-19 years old. Among these learners, 40 were considered as the experimental (in 2 different experimental groups), and the other 20 learners as the control. To gather data, these instruments have been used: a motivation questionnaire, a questionnaire about word games, a classroom atmosphere questionnaire, vocabulary tests, and teacher`s interview. Besides, 2 different categories of word games (cooperative versu