This thesis proposes a perspective on language and its development by starting from two approaches. The first is the ecological-enactive approach to cognition. In opposition to the widespread idea that cognition is information-processing in the brain, the ecological-enactive approach explains human cognition in relational terms, as skilful interactions with a sociomaterial environment shaped by practices. The second is the metalinguistic approach to language, which holds that reflexive or metalinguistic language use – talking about talking – is crucial for understanding language (...) and its development. In particular, I defend two theses: 1. A child’s initial communicative behaviour can be explained in terms of attentional actions: social actions that function by directing someone else’s attention. 2. In order for the child’s communicative behaviour to be sensitive to key properties of language, such as semantic content and normativity, she needs to learn metalinguistic skills. The development of this ecological-enactive perspective on language serves two functions. First, the ecological-enactive approach started by considering basic behaviour, such as locomotion and grasping. An approach in the cognitive sciences, however, should be able to account for the full gamut of human cognition. If the perspective developed in this thesis is viable, this is a contribution to extending the ecological-enactive approach to typically human forms of cognition. Second, this perspective throws new light on philosophical problems concerning language. In the different chapters, I deal with questions concerning the nature of linguistic knowledge, explanations of communicative behaviour, and the origins of semantic content and linguistic normativity. (shrink)