Developmental Milestones

We build our skills on what we’ve already learned. The skills summarized under each age range assume that the child has established prerequisite skills at an earlier age.

How to use this guide:

The information provided on this site is for educational purposes only. It is not intended to – nor SHOULD it – be used to screen or otherwise evaluate your child for speech, language, or social communication delays. It is not a complete inventory of typical child language development and does not take into consideration any variables that can affect development. In addition, this information includes limited details of the development of word and sentence grammar use and understanding, which are very important to the way older children interact with others. Finally, literacy milestones are not discussed. If you'd like to know about literacy development, you can read more here.

0 - 3 M

Coos with single syllable sounds (no meaning) Sighs...
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3 - 6 M

Soft babbling begins, with variety in tone Babbles to self or others Starts to engage in...
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6 - 9 M

More sounds show up in babbles (b, d, h, m, n, n, w, j, p) and are used in different com...
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9 - 12 M

Repeated-syllable babbles increase in amount and “sing-songiness”...
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12 - 18 M

Babbles (with some words in them) sound like sentences; can produce almost all consonant...
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18 - 24 M

A vocabulary of at least 50 single words used regularly, at least one new word used ever...
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24 - 30 M

Most words and phrases spoken are understood by strangers Pronunciation errors are commo...
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30 M - 3 Y

Some pronunciation errors exist, but child is understood almost all the time by familiar...
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3 - 3.5 Y

Common mispronunciations are all but gone, but speech is still difficult for all strange...
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3.5 - 4 Y

Strangers can understand almost all of what the child says, but child may continue to ma...
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4 - 4.5 Y

Pronunciation errors are almost all gone The majority of sentences used are at least 4 w...
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4.5 - 5 Y

Uses at least 1500 words Pronunciation errors are common in long, complex words, like �...
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5 - 6 Y

Speech is almost always understood No speech errors present by 5.5 y Makes complex sente...
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6 - 7 Y

Can use age-appropriate slang States the alphabet in correct order Counts to 100 Sentenc...
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7 - 9 Y

Language is used in a social way, with intention, to establish and affect relationships ...
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9 - 12 Y

Vocabulary used becomes far more abstract and sophisticated, mirroring that being learne...
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12 - 14 Y

Continued increase in use of abstract language Most sentences contain multiple clauses (...
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15 - 18 Y

Language is used for its own sake (to “just chat”) Single word vocabulary is 10,000 ...
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  • Carroll, D.W. (2004). Psychology of Language. Belmont: Thompson Wadsworth.
  • Davenport, M. & Hannahs, S.J. (2005). Introducing Phonetics & Phonology, Second Edition. New York: Oxford.
  • Hardie, R. G. (2005). Collins English Grammar. Glasgow: Harper Collins.
  • Kipping, P., Gard, A., Gilman, L., Gorman, J. (2012). Speech and Language Development [Poster]. Pro-Ed.
  • Owens, R. E. (2008). Language Development: An Introduction, Seventh Edition. Boston: Pearson.
  • Paul, R. (2007). Language Disorders from Infancy through Adolescence. St. Louis: Mosby Elsevier.

If you are concerned about your child’s development in speech, language, social skills, or literacy, please make a referral. You will not be kept waiting for months!