Physical & Motor Development:
Not all kids start to walk at the same time—some as early as 8 months, others as late as 17 months.
6 to 8 months: Learns to sit, develops neck strength, head control, balance, and coordination. May crawl between 6 and 10 months, or skip this and just walk.
8 months: Supports himself standing while holding on to something. Later, he will be taking sliding steps while holding on.
9 to 10 months: Pulls himself to stand holding on to a sturdy object—sofa or table leg. Figures out how to do deep knee bends to sit after standing.
11 months: Can stand unsupported – for a few seconds – and may also be able to walk while holding hands.
11 to 14 months: First steps! At 13 months, 3 out of 4 children are walking, though awkwardly.
Cognitive Development:
4 to 7 months: Knows his name now. When you say it, he'll turn toward you. More attuned to your tone of voice, he'll either react joyfully or become distressed and may cry. Begins to tell apart strangers and people he knows, and may cry when put him in the arms of someone he doesn't recognize.
8 to 12 months: Begins to understand simple requests. For example, say "no" when he tries to touch an electrical outlet; he'll pause, look at your face and maybe even shake his head "no" in return. Tests your responses to his behavior—not to be naughty, but to see what you'll do. Will later test you again to see whether you react the same way. Begins to associate gestures with certain actions and words—waves goodbye when someone leaves the room or shakes his head to refuse something to eat.
Social Development:
6 to 9 months: Prefers familiar people now; might show the first signs of separation anxiety (doesn't like being away from you). Shows interest in another baby by looking and grabbing at him or rolling toward him.
10 to 12 months: Enjoys playing near other children but still doesn't join them. Likes watching other kids, imitates their actions. Separation anxiety may get worse.
Language Development:
5 to 6 months Practices to make her voice rise and fall, often in response to baby talk and your facial expressions.
7 to 12 months Begins to babble with greater diversity, makes new sound combinations and intonations. Tries to imitate your speech, putting consonants and vowels together (like "bah-BAH-bah" or "dee-dee-dah"). He will have pretend conversations with you, taking turns "talking."