Grammar and Syntax is the study of how morphemes (the smallest unit of meaning) are put together. Grammatical morphemes apply inflection that signals meaning to nouns, verbs, and adjectives. Sources from these milestones are taken from Bown (http://members.tripod.com/Caroline_Bowen/?BrownStages.htm)

12 – 26 months

Children will begin to use

  • Between 1.0 – 3.0 average length of sentence
  • Present progressive – ING; “Crying”
  • Intonation to ask Yes/No questions
  • Uses limited WH – questions

27 – 30 months

Children will begin to use 

  • Between 2.0 – 3.5  average length of sentence
  • Regular plural -S; “Socks” 
  • Present Progressive -ING without an auxiliary; “Baby crying”
  • Semiauxiliaries; “Gonna”, “Gotta”, “Wanna”

31 – 34 months

Children will begin to use

  • Between 2.5 – 3.0 average length of sentence
  • Possessive -S; Girl’s hat
  • Present tense auxiliary; “Can”, “Will”, “Be”, “Do”

35 – 40 months 

Children will begin to use

  • Between 3.0 – 3.75 average length of sentence
  • past tense modals “Could”, “Would”, “Should”, “Must”, “Might”

4146 months

Children will begin to use

  • Between 3.75 – 4.5 average length of sentence
  • Uses locatives “Up”, “Down”, “Inside”, “Outside”
  • Uses “Be” verb + present progressive -ING; “The baby is crying”

 

47+ months

Children will begin to use

  • Between 4.5+ average length of sentence
  • Contractible auxiliary; ” The boy’s talking”
  • Uncontractible copula; “It is big”
  • Uncontractible auxiliary; “He is swimming”
  • Irregular third person singular; “She has it”
  • Past tense “Be” verb; “She was dancing”