During the first weeks of life, your baby will seem to be sending out a lot of signals. From birth, he will turn his head when you touch his cheek and extend his arms and legs and cry when he's startled. He'll also take a step forward when his feet touch a flat surface and grasp your finger when you stroke his palm. "Interestingly enough, none of these body signals is really about communicating," Dr. Speer says. "They're simply reflexes that your baby was born with." In a few months, some will disappear entirely, while others will evolve into more purposeful actions.

Of course, not all of your baby's early signals are mere reflexes. That gummy grin that surfaces at about 6 weeks, for example, is not gas. "Your baby's smiling isn't always a response to your actions, but it is a sign that he's happy," says Ron Marino, D.O., director of general pediatrics at Winthrop-University Hospital, in Mineola, New York. And as Dr. Marino notes, the timing couldn't be better. "Parents work so hard during those first six weeks -- it's nice to get some feedback."

 4 - 8 Months 
 
 By 4 months of age, your baby's physical signals will have become clearer as he begins to learn cause and effect and how to coordinate thought and action. He'll use signals to indicate his wants and needs -- raising his arms when he wants to be picked up, for example, or kicking his high chair when he's tired of sitting. Kelly Cederstrom, of Phoenix, can attest to this correlation. "At 4 months, my son Eric learned how to scoot," she recalls. "So whenever he wanted to play with me or his brother, Robby, he'd scoot in our direction."

This newfound understanding also enables your baby to initiate play directly. "When your baby drops his toy from his high chair for you to retrieve, he's not trying to annoy you," Dr. Marino says. "He's inviting you into a game."

Babies this age may also use body language to indicate that playtime is over. Such signals as turning away or breaking eye contact usually mean that your baby has had enough stimulation or simply wants to play with his toys on his own.

During this period, your baby will also baffle you with some gestures that don't seem even remotely connected to cause and effect. Like my daughter, your baby may tug her ears or roll her head back and forth to indicate that she is tired.
 
 9 - 12 Months 

For example, when 1-year-old Andrew Taylor, of Folsom, California, is hungry, he crawls over and thumps on the kitchen bread drawer, says his mother, Julie. "When he's thirsty, he stands in front of the refrigerator." Your child may also start to pair his signals with a variety of sounds. If he wants to be held, for example, he may lift up his arms and say, "Muh muh." If he wants his bottle, he may point to it and say, "Bah bah."

Before long, however, your child's body language will be replaced with simple words, phrases, and sentences. You can only hope that these first forays into verbal communication are as easy to decipher. 

Reff. Parents Magazine