Syntax Development – Learning To Speak In Sentences

Syntax is the ability to use words and phrases to construct coherent sentences to be used for communication. This form of language begins to develop after first words emerge and continues to grow at a rapid pace in the early years.

Average words per sentenceAge (in months)Behaviour
112 - 18
  • Nouns make up approximately 50% of phrases used
1 - 218 - 24

  • Children start to put two words together in sentences

  • Use of other types of words become included in phrases (e.g., verbs, prepositions)

  • Few grammatical markers used

  • Uses negatives in phrases (e.g., no, not)

  • Asks questions with raising pitch (e.g., “Daddy go?”)

2 - 324 - 36

  • Children begin to combine 3 or 4 words together

  • A variety of types of words are included in sentences (e.g., verbs, pronouns, prepositions, article, etc.)

  • Uses a variety of negation terms (e.g., no, not, can’t, don’t, etc.)

  • Uses basic “wh” questions (e.g., what, where)

436 - 48

  • Uses 4 or 5 words to form a sentence

  • Complex sentence forms start to emerge:

    • Prepositional clause – “The cat is under the chair”

    • Conjoined sentences – “I am tired and I want to sleep”

    • Simple infinitive – “I want to play”

    • Wh clauses – “I put it where I was sitting”



  • Sentences becoming more grammatically correct

  • Using more conjunctions in sentences (e.g., “I started to cry because I was scared”)

  • Asks a variety of question types (e.g., yes/no, what, where, who, why)

4 to 848 - 60

  • Basic sentence forms for conversation are acquired

  • Later developing complex sentence forms are emerging:
    • Relative clause – “My friend who sits next to me gave me her cookie”

    • Wh infinitive clauses – “I don’t know where to put it”

  • Vocabulary is becoming more advanced and new words are included into sentences regularly

  • Grammar becomes adult-like however errors still occur on higher level, complex sentence forms

  • Able to discuss past, present and future using correct sentence structures

  • Noun-verb agreement errors may still occur (e.g., “They wants to go”

  • Starts to include “if” and “so” in sentences

From Birth To First Words: Activities to Support Your Baby’s Language Learning Journey In the First Year Of Life