The present study contributes to the field of bilingual and trilingual language acquisition by analysing four multilingual families. In each family, at least one parent is bilingual. Following research questions will be addressed: (A) "How relevant are the (amount of) input and the (kind of) parental language strategies for language maintenance?" (B) "Which language choice can we observe in bilingual parents?" (C) "Is there a uniform definition for multilingual acquisition of immigrant languages?" (D) "Which language-external factors are possibly relevant for language transmission?" The results reveal that exposure in some languages is lower than 20%, a level regarded as possibly crucial for becoming a productive multilingual speaker (Quay [2008]. Dinner conversations with a trilingual two-year-old: Language socialisation in a multilingual context. "First Language," 28(1), 5-33). Some bilingual parents use the minority, others the majority language. Independently of the acquisition context, we claim it is unnecessary to label second- and third-generation children "heritage language speakers." Taking the family language policy approach, we believe language practices in families with at least one bilingual parent are largely understudied and should be analysed more carefully.