Your baby understands quite a bit by now -- probably a lot more than he shows. He's well acquainted with the word "no" -- although he doesn't necessarily obey it! He recognizes his name and turns when he hears it. He can also recognize familiar voices, even on the telephone.
He usually responds with body language to familiar questions, such as "Do you want up?" He may be able to follow simple, fun commands like "Get the ball." Once he's ready to follow directions, it will quickly become a favorite game. Just be sure to keep the directions simple, and don't ask him to do more than one thing at a time.
By now, your baby probably uses a few choice words like "dada," "mama," "baby," and "ball," but he doesn't always mean what he says. He talks for fun or just for practice. Still, you should try to figure out what he means. If he says "ball," he may want to play a game of "go get the ball." He'll get a big thrill if you can respond to his request. He'll know without a doubt that you're listening to him and understanding his words.
He's even more fluent in baby talk. Although you may not be able to understand what he's saying, you'll notice that his babbling is modeled after the patterns of speech he hears, complete with intonation, facial expressions, and even tongue sounds such as hisses and clicks. He may also test the volume on his vocal cords, seeing how loud he can shout and what reaction he gets. You may be afraid that he will be this loud forever, but this is just an exploratory stage that will pass. If you need to quiet him down, try whispering to him and encouraging him to imitate you.
Body language remains his favorite form of communication. He points, gestures, and uses facial expressions to get his message across. For example, he may raise his arms to ask to be picked up, or reach for the breast when he wants to nurse. He can also crawl onto your lap for a cuddle or practically jump from your arms when he wants to get down.
At this age, your baby can clearly remember things from the day before. He might imitate something you said or did yesterday, or he might seek out and find a favorite toy that he hasn't seen in a while. He also knows where to look to find intriguing objects such as the pots and pans behind the cabinet doors or the keys in your purse.
To help build up his memory, keep playing hide-and-seek games. Show him a toy and then place it under a piece of cloth. Watch him lift the cloth and discover it! You can also play with two pieces of cloth, allowing him to decide which one is hiding the toy. Another variation is to hide yourself. With baby following you, turn around a corner just out of sight and wait for him to figure out where you are. If he seems confused, pop your head out for a moment to get him back on track. As he masters this game, you can call his name from out of sight and let him follow the sound of your voice.
You can almost see his brain working as he makes one discovery after another. And there are still many more to come.
Sears, William and Martha. The Baby Book: Everything You Need to Know About Your Baby From Birth to Age Two. 2003. Little, Brown and Company.
University of Wisconsin Extension. Parenting the first year: month 12. 2006. http://learningstore.uwex.edu/Assets/pdfs/B3790-12.PDF