The acquisition of compositional meaning.

How do people create meaning from a string of sounds or pattern of dots? Insights into this process can be obtained from the way children acquire sentence meanings. According to the well-known principle of compositionality, the meaning of an expression is a function of the meanings of its parts and the way they are syntactically combined. However, children frequently seem to ignore syntactic structure in their sentence interpretations, suggesting that syntax is merely one of the sources of information constraining meaning and does not have a special status. A fundamental assumption in the argument in favour of compositionality is that speakers and listeners generally agree upon the meanings of sentences. Remarkably, however, children as listeners do not always understand what they are able to produce as speakers, and vice versa. For example, children's production of word order appears to develop ahead of their comprehension of word order in the acquisition of languages like English and Dutch. Such production-comprehension asymmetries are not uncommon in child language and motivate a view of compositionality as a principle pertaining to the result of perspective taking, and of meaning composition as a process of speaker-listener coordination. This article is part of the theme issue 'Towards mechanistic models of meaning composition'.