Children have to acquire 'communicative competence' (Hymes). This is how to use language appropriately and involves developing all the skills associated with conversation: they must learn when to speak, how to respond to others, which types of language are appropriate for which situations and so on.
Children are motivated to acquire language because it serves purposes and functions for them. Halliday identified 7 functions that language has for children in their early years.
1) INSTRUMENTAL - to obtain goods and services (express needs). e.g. 'I want'
2) REGULATORY - to control the behaviour of others e.g. 'do this', 'lets go'. This is directed to a particular individual and the verb normally comes first in order to make sure the message is direct and the point gets across quickly
3) INTERACTIONAL - to relate to others e.g. 'me and you'. This can come in the form of greetings, responses and names of people)
4) HEUISTIC - to explore and gain knowledge about the environment. 'Tell me why' (discovery).
5) PERSONAL - to express self e.g. 'me naughty' (awareness of self, expression of feelings).
6) IMAGINATIVE - to use language imaginatively (tell stories, jokes, create an imaginary environment). e.g. 'Let's pretend'
7) INFORMATIVE (AKA REPRESENTATIONAL) - to convey facts and information. e.g. 'I've got something to tell you'
Child directed speech - when talking to a child, we…