Language differentiation by the bilingual infant

This paper traces the process involved in the bilingual infant's gradual differentiation of his two languages, beginning with the acquisition of a dual lexicon. Word combination is at first based indiscriminately on this dual language source; function words account for a disproportionately large number of tokens used in mixed-language utterances. Universal principles of child syntax are at first applied; later, rules specific to each of the languages are developed separately. The development of self-awareness and sensitivity to standards in the second year provides the essential cognitive underpinning for the child to begin to avoid mixed-language utterances and to choose his language according to his interlocutor. At a still later point the bilingual older child may begin to make use of code-switching strategies appropriate to his or her bilingual community.