The present study aimed at indicating the effect of the affective variables (motivation, attitude, self-confidence and willingness to communicate) on the acquisition and learning of English language among the students of Languages and Translation Departments in the Kingdom of Saudi Arabia. The study participants were 40 students (20 males and 20 females) from the students specialized in English language. The study used three instruments: The semi-structured interview, affective variables questionnaire (AVQ) and English language proficiency observation checklist (ELPOC). The study adopted the quasi-experimental design mixed with the qualitative interpretation. The study employed the correlational analysis and the simple liner regression to indicate the relationship between the independent and dependant variables. The findings of the study showed that there is a positive significant relationship between the affective variables (motivation, attitude, self-confidence and willingness to communicate) and the process of English language acquisition as a second language. The study also demonstrated that the most influential factors in the learners' English language acquisition process is their willingness to communicate. Recommendations and suggestions based on the study results were directed to the L2 (EFL/ESL) instructors and all the specialists in English language acquisition and learning.