Roger Brown

The theory of 'mean Length of Utterance' (MLU)

Theory based around how long it takes children to learn to form a sentence.

He claimed that as children grew the length of their sentences naturally increased

The children progress through 5 different stages of language development

these provide a useful framework for professionals to determine the stage of a child's language development and to predict the next stage

'Morphemes' (units of grammar')

He noticed that in early stages, children did make errors, such as in tense, bu their word order (grammar) was correct

Five stages of language development

Stage 1

15-30 months

Joining two words, referred to as telegraphic speech (e.g. 'teddy gone')

Stage 2

28-36 months

Naming of objects, describing experiences with use of 'ing' endings (e.g. 'coming'), the inclusion of 'in' and 'on', and use of 's' plurals (e.g. 'cars')

Stage 3

36-42 months

Using past tense (e.g. 'went'), and possessives (e.g. 'Mummy's car')

Stage 4

40-46 months

Speaking sentences with more complex use of past tense (e.g. 'jumped') and articles (e.g. 'a', 'the')

Stage 5

42-52+ months

making more complex sentences with use of contractions (e.g. 'we've') and third person irregular (e.g. 'he does')

Criticisms

The study sample was restricted to only 3 children

He did not account for meaning, but only looked at the length of what was said

His framework cannot be used to measure the clarity of speech

children develop at different rates so the theory may not apply for all children

It doesn’t take into account whether or not the child has a disability causing problems with their linguistic development.

If another area of development has been affected for some reason then their linguistic development may also be affected.

Adults / carers imitate and copy the childs speech and their replies are used as a role model so the children then can pick up new vocabulary

Children’s conversations concern the immediate

Holophrases – children use one word for lots of different meanings, changing the sound slightly and using gestures and symbols.