The three stages of CLA (learn this as a guideline in the exam)

Stage one - holophrastic (one word):
Age: 12-18 months
What happens: The child utters their first word. She/he then builds a vocabulary of holophrases (single words used to convey meaning). They convey all the meaning of a phrase/sentence through body language, inotation and volume.

Stage two - Two words a.k.a - the emergence of grammar. This supports Chomsky's LAD. Two word phrases like "all gone!". It is the beginning of structure.

Stage three - Telegraphic:
Age: 2-2 and a half years
What happens: The child begins to use sentences of up to four words in length.
-Sentences with gaps in them where the non-lexical words (those without a 'dictionary meaning') like 'but', 'and', 'if' (conjunctions) 'the', 'a' (articles), 'is', 'has' (auxiliary verbs), as well as endings such as 'ing' are often omitted.
-Children combine 3-4 words in a variety of grammatical constructions: declarative syntax, interrogative syntax (for adjacency pairs - to teach chaining), and imperative syntax (because they lack politeness strategies).
-After age three, children's language advances in leaps and bounds.
-Although massive developments happen simultaneously and are linked together.
-Grammar: The structure of the language (word order, sentence types, word endings, tenses, using negatives, passives and conjunctions).
-Semantics: The meaning of words (the usage, growth and comprehension of vocabulary).
-Phonology: The sounds of the language (inotation, stress, pitch, tone, pronunciation). -Pragmatics: Everything else. Or, the ability to use language that is appropriate to the situation, the rule of conversation (turn-taking, politeness, terms of address), initiate a conversation, how to keep it going, how to keep someone's attention, how to get someone to do what you want and make them feel like it was their idea, and so on.