How well does the development of children's understanding of English grammar support any one of the theories of language acquisition which you have studied?

Chomsky believed that all languages have different surface structures but all share the same deep structure; phrases containing a subject, verb and object are common in all languages.  Even when children are using telegraphic speech and are missing out grammatical function words and word endings the deep structure remains.  For example ‘man kick ball’.  Children possess knowledge of this structure from birth and this explains why they can learn language at such an incredible speed.  

Linguistic universals throughout all languages can also be explained by Chomkys theory.  The innateness theory explains why children from all cultures pass through similar stages of language acquisition and development. Evidence (see ‘Revision Express - English Language AS an A2’) suggests that children of a different language base will apparently acquire language at roughly the same.

Evidence shows that children begin to use and improve their language skills in their second year whether they are actually ‘taught’ or not.  It seems from this that children are using a Language Acquisition Device; as long as they are exposed to language the LAD helps them to use primary linguistic data (input) to speak (output).  Evidence also suggests that people who aren’t exposed to language in the first few years of their life (‘critical period’), when they are using their LAD, don’t learn the language sufficiently.

When considering how to support the innateness theory one must also consider the impact that other theories have on children’s development of language.  The Imitation and Reinforcement (B.F Skinner) theories suggest that children learn how to produce correct phrases etc. because they are reinforced but this doesn’t explain how a child can create structural rules for themselves for use in the future.  Only the innateness theory can account for this.

Children use their Language Acquisition Device in order to use the correct inflections when they form the past tense or pluralise.  The innateness theory is also supported by the fact that children use their LAD to get uncommon plurals and past tenses wrong as they are following regular grammatical rules.  For instance using the common grammatical rule a child may put ‘–ed’ on the end of a word (‘loved’ for instance) to form the past tense.  However using these same rules provided by the LAD s/he may say ‘comed’ instead of ‘came’.  This shows the innateness theory in action.

In conclusion I believe that the Chomsky’s innateness theory plays a big part in the language acquisition of children, however I also think that the Cognitive theory and interaction are needed to ensure that the child becomes fluent in the language.