Although Bilingual First Language Acquisition research has increased considerably over the past few decades, there is still much controversy regarding the rate of development, i.e. the question whether bilinguals lag behind their monolingual peers in various aspects of language. Some studies have found similar rates of development, whereas others have found that bilingual children lag behind their monolingual peers. The current study contributes to this discussion of (dis)similar rates of development by investigating bilingual children’s acquisition of German complex sentence constructions involving adverbial clauses (ACs). Our findings are consistent with usage-based approaches to language acquisition, which predict that bilingual acquisition should proceed slower due to learners having less exposure, on average, to each language.