I gave my son solids at 5 months. He started on rice cereal, them moved to bananas, mangos, peas, and the like. I followed the guidelines in the Super Baby Food book - which are very different from other books I've seen. (My son, for instance, didn't get most berries until after he was a year old. Lost of kids in his playgroup were having them at 9 and 10 months.)That said, I have a friend who didn't start her kids on solids until they were 9 and 10 months old. They just weren't interested before that. Know what? THEY'RE FINE, and super smart.Go with your gut, not with what we did. If your child is 4 months and doing great on a bottle, stick with the bottle. If he/she is 4 months and clearly hungry, try out solids. There's a million methods and a millions experts who will tell you a million "this is the way it must be done" rules. Best way to navigate: go with your gut.