Language Development Timeline

Period: Jan 1, 1993 to Apr 1, 1993

Birth-3 months
Period: Apr 1, 1993 to Aug 1, 1993

3 Months- 7 months

Vocally Responds to Partners and Caregivers.
Period: Aug 1, 1993 to Jan 1, 1994

8 months- 12 months

Begins Gesturing
Period: Jan 1, 1994 to Jun 1, 1994

12 months- 18 months

First Words Spoken, words filled intentions previously signaled by gestures
Period: Jun 1, 1994 to Jan 1, 1995

2 Years

Begins adding bound morphemes, Average length or mean length of utterance (MLU) is 1.6 - 2.2 morphemes
Period: Jan 1, 1995 to Jan 1, 1996

3 Years

More complex syntax structure, MLU is now 3.0-3.3 morphemes
Period: Jan 1, 1996 to Jan 1, 1997

4 Years

Begins to change style of talking to fit conversational partner. MLU is 3.6-4.7 morphemes
Period: Jan 1, 1997 to Jan 1, 1998

5 Years

Ninety percent of language form is learned.

Birth-3 months