Brown's stages of morphological development

Question 1

stage 1:

what age in months

MLU =

MLU range

morphological structure

Answer 1

15-30

1.75

1.5-2.0

combine basic words

Question 2

Stage II:

age in months:

MLU

MLU range

morphological structure

Answer 2

28-36

2.25

2.0-2.5

present progressive (-ing endings on verbs)
in
on
-s plurals

Question 3

Stage III:
age in months

MLU

MLU range

morphological structure

Answer 3

36-42

2.75

2.5-3.0

irregular past tense

-s possessibe

uncontractible copula ( the full form of the verb to be when it is the only verb in the sentence ) “are they here ?” “is she coming”

Question 4

Stage IV: age in months

MLU

MLU range

morphologicla structure:

Answer 4

40-46

3.5

3.0-3.7

articles

regular past tense

third person regular present tense

Question 5

Stage V

age in months

MLU

MLU range

morphological structure

Answer 5

42-52

4.0

3.7-4.5

third person irregular

uncontractible auxiliary

contractible copula

contractible auxiliary