From the January 2002 Early Childhood newsletter.

Some advice from Dr. Hart on speech and language delays:

• Children's words begin to become recognizable at about 18-20 months of age. By that time, they will likely be using words frequently. However, typical children do deviate from this timetable and Dr. Hart says parents should not be too concerned about simply a lack of words. Rather, parents should focus on their child's overall social skills and behavior. If a child doesn't like interaction and often looks away from others, or suddenly stops talking or babbling, parents should seek an evaluation.
  
  
• Often, a child may be slow to talk because of a mismatch between his or her temperament and that of the parents. The child may be more outgoing than his or her parents, or more subdued. Says Dr. Hart: "It takes a while to figure out how much interaction is comfortable, to prevent overstimulation."
  
  
• If a child doesn't receive enough interaction at home, Dr. Hart recommends enrolling the child in a group care situation. This way, he or she will be able to interact with teachers and peers throughout the day. Dr. Hart stresses that parents should visit a child care setting and make sure there is a lot of interaction between adults and all of the children. "You want continuous talk," she says, a positive environment with no yelling.
  
  
• Dr. Hart emphasizes that studies show late talkers do catch up to their peers in the area of communication and language skills. "That's why pediatricians tell parents not to worry. A child won't be delayed because they're late [to talk]."

Dr. Hart is a co-author of The Social World of Children Learning to Talk, a fascinating account, based on a 2-1/2 year study, of how children's speech practices and family interaction affects learning to talk.