Brown's Stages of Language Development

Stage l Age

12-26 months

Stage l MLU

1.0-2.0

Stage l syntactic milestones

- Uses one, two, three word utterances

- Uses intonation to ask yes/no question

- Uses limited Wh-questions

Stage ll Age

27 -30 months

Stage ll MLU

2.0-2.5

Stage ll Syntactic milestones

- Begin to use grammatical morphemes (Walk vs. Walking)

- Use locatives and prepostions (In and On)

Stage lll Age

31-34 months

Stage lll MLU

2.5-3.0

Stage lll Syntactic milestones

- Sentence increases in length due to uses of copula 'be" ("I am McKenzie", "Mommy is here")

- Increases usage of wh-questions

- Uses interrogative reversale ("was mom here?)

Stage lV Age

35-40 months

Stage lV MLU

3.0-3.75

Stage lV Syntactic milestones

Uses noun-phrase as object complement

- Uses indirect or embedded Wh-questions (Complex sentence - "Where are you ----> I know where you are?"

Stage V Age

41-46 months

Stage V MLU

3.75 to 4.5

Stage V syntactic milestones

- Coordinates simple sentences, mainly with "and" (Compound Sentence)

- Increase usage of locatives (up, down)

Stage V+ Age

47+ months

Stage V+ MLU

4.5+

Stage V+ Syntactic milestones

- Uses negative interrogatives (Don't you want to go?"

- Uses indefiniate pronouns such as nobody, noone

- Continue to have difficulties with double negatives ( all human have difficulties with this)