This paper attempts to elucidate the relationship between linguistic form, interactional strategies and social meaning on the basis of a detailed study of a natural conversation. The investigation is based on a conversation recorded in an institution for Mexican immigrants by a linguist, a native American of Mexican ancestry, and program advisor of the institution. His interlocutor was a community counselor employed in the program. Two types of information were utilized. Turns containing a code switch were first examined as to their place within the structure of the total conversation. Then the switched phrase was substituted with a phrase from the other language to determine what the code switch contributed to the meaning of the whole passage. These examples of bilingual communication indicate that language usage is closely tied to the position of Chicanos as a minority group within the English-speaking majority. Selection of alternate forms is related to a variety of social factors such as ethnic identity, age and sex, and degree of solidarity or confidentiality. (CFM)