摘要：This paper investigated whether bilingual codeswitching (CS)9 the alternation between languages intra-sententially，and the use of discourse markers (DM)，e.g. “well”，“like”，“sort of9, are indicators of impairment or fluency in bilingual individuals with diagnosed aphasia What motivates CS from the preferred language to the less preferred language and vice versa is of interest from linguistic, social and psychological perspectives. The Sociopragmatic-Psycholinguistic model (Walters, 2005) is an integrative model that distinguishes between social, pragmatic, psychological and linguistic motivations í5r CS. For example, sociopragmatic CS is ffgoal-driven and motivated by identity as well as external, contextual fectors1*, such as for emphasis and focus, to show ?ntrast, to quote from someone, to confirm the listener understood, to mark repetition of a word or phrase, to index a translated segment, to show ethnic or group solidarity, femiliarity, empathy with a listener, or to indicate a change in setting, role, or topic. Structural-psycholinguistic CS, however, "stems from individual linguistic and mental fectors’’，due to word retrieval and fluency difficulties and/or higher frequency of parallel lexical items and phrases.
