This study is an investigation into the contribution of bilingualism to learning English as a foreign language; and the limited and judicious use of mother tongue in EFL classroom does not reduce students’ communicative ability but can assist in teaching learning process. It proposes an explanation for this, based on the historical development of bilingualism over time that has remained the dominant practice in English language classes in Pakistan. Moreover, it seeks to understand whether teachers and the learners who do have another language draw on it in ways relevant to the teaching of English, and to suggest reasons why learners’ and teachers’ languages are disregarded in the teaching and learning process. In doing so, the dissertation draws on key bodies of literature in bilingualism, second language acquisition and critical studies in an attempt to provide a framework for considering the research questions. The study employed a qualitative, interpretive research design involving questionnaires, classroom observations and semi-structured interviews. The data chapter analyzed the students and the teachers’ expressed responses and beliefs about the role of learners’ first language(s) (L1) in the EFL class. The findings of the study in general are that bilingualism as a resource in teaching aids and facilitates in learning L2. There are differences between bilingual and monolingual teachers in that the former have much richer resources on which to draw. There are added insights which come from circumstantial or elective bilingual experience, from being a non- native English speaker, and from formal and informal learning experience. These propositions are discussed in the light of the writings of critical theorists to give a wider perspective on bilingualism as a teaching aid. It is suggested that bilingualism as a teaching aid should become a legitimate topic for discussion and further research.