1. Writing about Grammatical Development

2. A Reminder About the Telegraphic and Post-telegraphic Stages
From the age of about 2, children begin producing three and four word utterances. Some will be grammatically complete such as ‘Amy likes tea’ or ‘Mummy sleeps upstairs’ but others will have essential grammatical elements missing such as ‘Daddy home now’ or ‘Laura broke plate’. These utterances are similar to some of those used in the two-word stage – they can often make sense, but key elements are missing such as:
Articles – ‘a’ ‘the’
Auxiliary verbs – ‘is’ ‘has’
Prepositions- ‘to’ ‘on’ ‘for’
Conjunctions – ‘but’ ‘because’
Progress during this stage is rapid, and by the age of 5, children have usually mastered sentences containing more than one clause, conjunctions and ‘ing’ ‘ed’ or ‘s’ endings to words and verbs. These are known as inflectional affixes.
Affixes is the general term for prefixes (morphemes added to the beginning of a root word) and suffixes (which are added to the end).

3. Acquisition of Inflections
Research indicates there is a predictable pattern in the acquisition of inflectional affixes. These are word endings such as –ed and –ing. Functional words such as articles like ‘a’ and ‘the’ and also auxiliary verbs seem to be acquired in a regular order.
Brown (1973) studied children’s language development between the ages of 20 months and 36 months and found the sequence shown below occurred regularly. The features are also listed in the order in which they were acquired:
1) –ing
2) plural ‘-s’
3) possessive ‘-s’
4) the, a
5) past tense –ed
6) third person singular verb ending – s (eg): he sings
7) auxiliary verb ‘be’ (eg): I am dancing

4. Cruttenden (1979) divided the acquisition of inflections into the following three stages:
1) In the first stage, children memorise words on an individual basis
2) In the second stage they show an awareness of the general rules of inflections. They observe that past tense forms usually end in –ed so instead of ‘ran’ they say ‘runned’. This kind of error is known as Overgeneralisation.
3) In the third stage, correct inflections are used

5. Understanding Grammatical Rules
Children produce accurate grammatical constructions from an early age, and researchers have tried to determine if they have learned this themselves or have copied adult speech.
A famous experiment was carried out by Jean Berko (1958) who showed children pictures of fictitious creatures he called ‘Wugs’. At first, the child was shown a picture of one creature and told ‘this is a Wug’. Then, they were shown a picture of two Wugs, and the children were asked to complete the sentence ‘Now there are two…’. Children aged 3 and 4 replied ‘Wugs’. As they could never have heard this word before, it because clear that they were applying the rule that plural end in ‘-s’/
However, children between the ages of 2 and a half and 5 often OVERGENERALISE’ with plurals, so we hear things like ’sheeps’ and mouses’.

6. Asking Questions
Research suggests this happens in three stages:
1) Relying on intonation in the two-word stage eg: daddy home? Said with a rising tone
2) During their second year children acquire question words such as ‘what’ and ‘where’ resulting in questions such as ‘where daddy gone?’ They can’t yet use auxiliary verbs such as ‘has’
3) In their third year, children can use auxiliary verbs and learn to say ‘is Joe here?’ however, they can’t always use wh-words correctly yet and might say things like ‘why Joe isn’t here?’

7. Negatives
This also happens in three stages:
1) Words ‘no’ and ‘not’ are used in front of other expressions eg) no want
2) During the third year ‘don’t’ and ‘can’t are used eg) I don’t want it
3) In the third stage more negative forms are acquired such as ‘didn’t’ and ‘isn’t’ and negative constructions are used more accurately.

8. Example 2
Kate (2 yrs 6 mths) is sitting on the knee of a family friend.
Adult (pointing to one of Kate's feet) What's that?
Kate A footsie
Adult (pointing to both feet) What are these?
Kate Two footsies - no, two feetsies, I mean.
Here language is being used as a ritual adult/child game rather than for purposes of genuine instruction. In this example there is evidence of the child's awareness of a rule and its self-correction. The rules are complicated by the child's use of the baby talk form footsie. Kate remembers that the irregular plural of foot is feet and not foots, but then she inflects the corrected plural with -s to form a double plural: feetsies. The "I mean" draws attention to the change as the self-conscious and deliberate correction of a slip.

9. Jess: I not know.
With reference to grammar and discourse structure, Jess appears to make a few virtuous errors and inflections. However, this does support her movement from the two-word to the telegraphic stages. On line 2 Jess says ‘I not know’ and drops the auxiliary verb ‘do’. This could be because Jess is maybe trying to say ‘I do not know’ which will become to shortened to ‘I don’t know’. Jess’s mum did not correct her, perhaps this is due to her believing that correction can slow down a child’s language development. Chomsky argues that children have a built in language acquisition device that enables them to instinctively learn language correctly as they get older.

10. Mother: What’s that? Briony: What’s that?
Briony’s mother continues initiating interrogative utterances for turn-taking ‘What’s that?’ but Briony chooses to repeat and form her own question directly back at her mother ‘What’s that?’. Briony breaks down the contractions by repeating the interrogative using the auxiliary verb ‘is’ between ‘what’ and the demonstrative pronoun.