Your toddler knows a lot of words and probably has said a few of them, too -- "doggie," "book," "bottle." But between 18 and 24 months, he'll discover that stringing a few words together gives them new meanings that help you better understand him. He'll start by using "telegraphic speech," simple sentences consisting of a noun and verb, say -- "Doggie bark!" "Read book!" "Want bottle!" -- the only words he needs to get his point across to you, says Ann Kummer, Ph.D., director of the Speech Pathology Department at Cincinnati Children's Hospital Medical Center.
To encourage more complex sentences, "parallel talk" with your child: Describe what you're doing as you're doing it, whether it's getting dressed or chopping vegetables, and encourage him to repeat what you've said. You might also try acknowledging his simple sentences by repeating what he said in more complicated ways. If he says "Doggie bark," for instance, you might say, "Yes, the doggie is barking." Soon he'll be chatting up a storm.