This chapter describes the patterns of language use in one bilingual Semai community and identifies factors influencing language behavior. In investigating the central question “Who speaks what language to whom, where and to what end?” (Fishman, 1991), it was found that while the Semai language is used for daily interactions within the group, the Malay language is used for communication with the wider community. Socio-psychological factors, such as high perception of Semai vitality and positive attitude towards their language, which they see as a substantial part of their cultural identity, are found to be motivating factors in language maintenance. The findings suggest that community members’ choices in language use constitute acts of agency aimed at passing on their language to the next generation.