Linguists are often talking about evolution these days, but language structures are rarely explained by evolutionary adaptation. But in this talk, I claim that a wide range of structures (e.g. phoneme inventories, case-marking patterns, word order patterns, causative constructions, subordinate-clause constructions) can be explained as adapted to their “environments”, i.e. the needs of language users. Why has this often been overlooked by linguists? I will show that this is because linguists have often confused language-particular explanations with general explanations, and biolinguistic explanations with explanations in terms of cultural evolution. Once these distinctions are made, it should become clear that the majority of successful general explanations of language structure are based on evolutionary adaptation.