The issue of whether personality changes as a function of language is controversial. The present research tested the cultural accommodation hypothesis by examining the impact of language use on personality as perceived by the self and by others. In Study 1, Hong Kong Chinese-English bilinguals responded to personality inventories in Chinese or English on perceived traits for themselves, typical native speakers of Chinese, and typical native speakers of English. Study 2 adopted a repeated measures design and collected data at three time points from written measures and actual conversations to examine whether bilinguals exhibited different patterns of personality, each associated with one of their two languages and the ethnicity of their interlocutors. Self-reports and behavioral observations confirmed the effects of perceived cultural norms, language priming, and interlocutor ethnicity on various personality dimensions. It is suggested that use of a second language accesses the perceived cultural norms of the group most associated with that language, especially its prototypic trait profiles, thus activating behavioral expressions of personality that are appropriate in the corresponding linguistic-social context.