Children's Age-by-Age Guide: 9 to 12 Months

Emotional Milestones

Your baby's self-esteem is beginning to emerge. He'll love to smile at, pat, or even kiss his image in the mirror. He's going to need lots of positive reactions from you -- a clap of your hands when he picks up a toy and manipulates it, or encouraging words when he manages to cruise all the way around the living room. He wants and needs you to participate in his life now, not just stand by and watch. This also means that now is the time to start setting limits for him; he'll begin testing you and needs you to be firm and consistent in disciplining him.

Smart Strategy:

Your little one's burgeoning sense of self means he is growing more independent -- and that complicates your role. He needs you to give him time to play and learn on his own (while keeping an eye on him so he stays safe, of course). Learn to communicate with him from across the room. If he's stacking blocks while you're emptying the dishwasher, stay involved by encouraging him with your words, but don't physically help him unless he becomes extremely frustrated. Your enthusiasm will enhance his sense of accomplishment. In effect, you're encouraging him to discover his own capabilities while also letting him know you're there for him if he needs you.

You'll be delighted as you see your baby's ability to understand words and link them to gestures now. She'll wave "bye, bye," and shake her head "no." She'll say "Dada" and "Mama." She'll point to an object she wants and won't understand if she can't have it -- you'll see her frustration escalate over not getting what she wants. A one-year-old is no longer satisfied with doing the same thing over and over; she's curious about everything.

Smart Strategy:

Your baby may not be able to actually tell you which toy she prefers or which foods she wants, but when she abandons one plaything for another or grabs at pieces of cheese and refuses cereal, she's sending you a message. You can help lessen her frustration by picking up on the signals about her likes and dislikes. It's very important that you stay attuned to her preferences and give in to them. At this stage, save the hard and fast rules for matters of safety.

• 6 to 18 months -- Third dose of Hepatitis B (Hep B), if child hasn't already had it.
• 6 to 18 months -- Third dose of Inactivated polio (IPV), if child hasn't already had it.