All human communities have, and use, language. Language allows humans to refer to objects, properties, actions, abstract entities, and other aspects of the world, and to convey and retrieve thoughts in a way that seems both fast and effortless. Both in its complexity and internal structure and in its expressive power, human language is well beyond any communicative system available to nonhumans. This entry surveys some basic empirical evidence and theorizing about the nature and properties of human language, the way language is produced and understood, and the way language is acquired by children.