You want your infant to say "Dada," but she cries "cookie" instead. How do you get her to say the words you want to hear? Try some key talking points.

Babies usually begin to babble between 12 and 18 months, says Roberta Michnick Golinkoff, a professor of psychology at the University of Delaware and co-author of the book How Babies Talk. She and co-author Kathy Hirsh-Pasek have found that "if all the cues are in alignment, a 12-month-old can learn words from just a few exposures." First, instructs Golinkoff, pick an eye-catching object. Then highlight the object by looking at it or pointing to it. Finally, repeat the name of the object at least five times.

Your infant may remain silent after this coaching session—but that doesn't mean she didn't get it. "Even 12-month-olds who can't say a thing show that they have learned the new word," says Golinkoff. When you say the name of the object, her research shows, babies will stare at it longer than at an unnamed object.

This finding sheds light on why most babies utter words slowly at first, perhaps one a week, then suddenly say as many as 40 in that time. They must be waiting for the perfect moment to impress you.