|1-6 months||Coos in response to voice*|
|10-11 months||Imitation of sounds; says "mama/dada" without meaning|
|12 months||Says "mama/dada" with meaning; often imitates two- and three-syllable words|
|13-15 months||Vocabulary of four to seven words in addition to jargon; <20% of speech understood by strangers|
|16-18 months||Vocabulary of 10 words; some echolalia and extensive jargon; 20 to 25% of speech understood by strangers|
|19-21 months||Vocabulary of 20 words; 50% of speech understood by strangers|
|22-24 months||Vocabulary >50 words; two-word phrases; dropping out of jargon; 60 to 70% of speech understood by strangers|
|2-2.5 years||Vocabulary of 400 words, including names; two- to three-word phrases; use of pronouns, diminishing echolalia; 75% of speech understood by strangers|
|2.5 to 3 years||Use of plurals and past tense; knows age and sex; counts three objects correctly; three to five words per sentence; 80 to 90% of speech understood by strangers|
|3 to 4 years||Three to six words per sentence; asks questions, converses, related experiences, tells stories; almost all speech understood by strangers|
|4 to 5 years||Six to eight words per sentence; names four colors; counts 10 pennies correctly|
|Author:||Lynne M Kerr, MD, PhD - 9/2008|
|Content Last Updated:||6/2011|
Schwartz, ER ed.
Pediatric Primary Care: A Problem-Oriented Approach.
St. Louis: Mosby; 1997. 0815180543 http://www.amazon.com/exec/obidos/tg/detail/-/0815180543/qid=110815752...
The Children's Hospital of Philadelphia, PA. Extensive reference for practitioners in office-based pediatric care. Previous edition: c1990. Softcover. DNLM: Pediatrics.