Inteaction determines and affects the conditions of language acquisition especially in contexts where exposure to the target language is limited. This is believed to be successful only within the context of small classes (Chavez, 2009). This paper examines learners' progress resulting from interaction in large classes. Using pre-, post-, and delayed post-test, results from two groups of participants (n = 78 and 83) involved in the study do not show any significant difference at post- and delayed post-test. The study, therefore, rejects the argument that class size constrains interaction and instead argues that the durability of knowledge gained from interaction appears to have a stronger correlation with type of interaction, learners' previous learning styles, proficiency, and the wider context of learning. The paper also argues that teacher-led interaction is not only possible with low proficiency, but could lead to outcomes which actually define the purpose for which language is learnt.