At nine months, the pace of your baby's exploration is increasing. He also has a better ability to remember and to solve problems. Enjoy playing together at this delightful age. (The following information has been adapted from Dr. Segal's book series, "Your Child at Play.")
Tie several colorful scarves together. Insert one end into a cardboard tube and let him pull them out. See if he's able to stuff them back inside.
Place three toys in a box. Name one, and ask him to give it to you. If he gets it wrong, name the toy he gave you. If he gets it right, say, "Yes, that's a...."
Give his teddy bear an occasional sip when your baby is learning to use a cup. This is a forerunner of later imaginative play.
Take time to sit down with him. He might initiate a game, or you can give him a jump-start by placing a basket of new and interesting items within his reach.
Play back-and-forth games: He'll hand an object to you, and then you hand it back to him, and so on.
Turn toys upside down and put them in front of him. Encourage him to turn the toys right side up. He's learning the difference.
Put some of his toys in a plastic see-through box. Let him try to take the cover off himself. If he has trouble, help him.