This study investigated whether language context affects language choice in a Spanish-English bilingual infant from age 1;3 to 1;10. Most studies of child bilingualism assume that communicative competence occurs at a stage in language development after the onset of syntactic constructions, but this paper hypothesizes that once the child begins to acquire equivalents (Spanish-English lexical pairs like casa-house) at about age 1;3, she is able to use contextual clues to choose the appropriate equivalent as determined by the language spoken by her adult interlocutors. Equivalents are analyzed according to their distribution in the speech of the child when interacting with different adult interlocutors. Results indicate that communicative competence is acquired even earlier than previously suggested. The study's bilingual subject used her developing languages in contextually sensitive ways before age 1;10. This study has provided a means of investigating communicative competence from the first words and shows that communicative competence is acquired very early as a consequence of language socialization. (Contains 6 references.) (Author/AA)