Here is a good summary of baby language development milestones.
Birth to 3 Months
Infants make a variety of noises, including crying, gurgling, and cooing. They recognize parents’ voices, become quiet when spoken to, and increase or decrease sucking in response to sounds.
4 to 6 Months
Babies’ noises evolve into babbling (”mamamama,” “dadadada”). They seem excited by their new “speech.” Babies move their eyes in the direction of sounds, may cry in response to harsh voices, pay attention to music, and notice toys that make sounds.
7 to 12 Months
Babies’ babbling becomes longer, and they repeat sounds, listen when spoken to, and recognize words for common items, such as “book” and “juice.” They begin responding to simple commands, and, at a year, they typically say their first word.
Over 12 months
Between 1 and 2 years, toddlers should be able point to body parts and pictures in a book and follow such commands as “Kiss the baby” and “Show me your shoe.” At 2, children usually say two-word sentences, and at 3, three-word sentences.
American Speech-Language-Hearing Association
Offers informative publications, a help line, and referrals to audiologists and speech-language pathologists (www.asha.org or 800-638-8255)
All Children’s Hospital, St. Petersburg, FL
Provides comprehensive information on recognizing and treating speech and language delays (www.helpforkidsspeech.org)
Zero to Three
Offers information on development and parenting tips (www.zerotothree.org or 202-638-1144)
A government-sponsored organization with links to services for children with disabilities and delays (www.childfindidea.org/links.htm)