Learners of second language possess different characteristics that make them different from each other. Intelligence is one of these characteristics, which is considered to affect the acquisition of formal structure of a second language when taught in a formal setting. However, it is thought to not affect the development of communicative competence of the language. The research aims at finding out whether this claim is true or not. In order to do so, 20 tertiary level students learning English as a second language were tested in terms of their intelligence, grammatical proficiency and communicative competence. The results then were compared to find out the relationship among these variables to determine the effectiveness of intelligence on second language acquisition in terms of grammatical structures of the language and also in terms of communicative in Bangladeshi context.
