Language Development (Davis & Brown)
Quick revise

David Crystal (1996)

Cries, Burps and Burbles




In the first two or three months of life an infant makes lots of noises of pain, hunger and discomfort, to which parents learn to respond, but it is difficult to attribute specific meanings to these sounds.

Cooing and going gaga

Most children add a new variety of sounds to their repertoire before they are six months old – the ‘cooing’ which may resemble some of the first sounds of speech.

Babbling on

This evolves into babbling – the first extended repetitions by children of some basic phonemic combinations such as ‘babababa’ etc.

First Words

From out of these streams of sounds eventually emerge a small repertoire of utterances that sound something like a word.  However, these single words may appear to serve a multitude of functions or to have more than one meaning.


Mean Length of Utterance (MLU), Roger Brown (1969)

MLU is used to define stages of Child Language Acquisition.  MLU is calculated by dividing the total number of words (morphemes – smallest meaningful part of a word) spoken by the number of utterances a child makes.  So if a baby used two words in two utterances the MLU would be one.  Brown has related MLU scores to stages of CLA:

MLU Score


1.1 – 2.0


2.0 – 2.5


2.5 – 3.0


3.0 – 3.5


3.5 – 4.0



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