Typical Milestones in the Development of Language and Speech

Age Receptive Skills Expressive Skills
Turns to source of sound
Shows preference for voices
Shows interest in faces
2 to 4 months  
Takes turns cooing
6 months Responds to name Babbles
9 months Understands verbal routines (wave bye-bye)
Says ma-ma, da-da
12 months Follows a verbal command
Uses jargon
Says first words
15 months Points to body parts by name Learns words slowly
18 to 24 months Understands sentences
Learns words quickly
Uses two-word phrases
24 to 36 months
Follows two-step commands
Answer questions
Phrases 50% intelligible
Builds three- (or more) word sentences
Asks “what” questions
36 to 48 months Understands much of what is said
Asks “why” questions
Sentences 75% intelligible
Masters the early acquired speech sounds: m, b, y, n, w, d, p, and h
48 to 60 months
Understands much of what is said,
commensurate with cognitive level
Creates well-formed sentences
Tells stories
100% intelligible
6 years   Pronounces most speech sounds correctly; may have difficulty with sh, th as in think, s, z, th as in the, l, r, and the s in treasure
7 years   Pronounces speech sounds correctly, including consonant blends such as sp, tr, bl