WHAT TO WATCH FOR
There is a good deal of variation in abilities among 9- to 12-month olds, but you should talk to your pediatrician if you have concerns, or if your baby does not:
Search for hidden objects by 12 months
Point to things and look at pictures by 12 months
Crawl, pull to a stand, cruise, or walk in some fashion by 12 months
Respond to games such as peek-a-boo and pat-a-cake by 12 months
Babble and imitate sounds
Seem to understand simple words (mama, ball), wave good-bye, or follow simple commands