Genetic makeup will, in part, determine intelligence and speech and language development. However, a lot of it depends on environment. Is a child adequately stimulated at home or at childcare? Are there opportunities for communication exchange and participation? What kind of feedback does the child get?
When speech, language, hearing, or developmental problems do exist, early intervention can provide the help a child needs. And when you have a better understanding of why your child isn't talking, you can learn ways to encourage speech development.
Here are a few general tips to use at home:
Spend a lot of time communicating with your child, even during infancy — talk, sing, and encourage imitation of sounds and gestures.
Read to your child, starting as early as 6 months. You don't have to finish a whole book, but look for age-appropriate soft or board books or picture books that encourage kids to look while you name the pictures. Try starting with books with textures that kids can touch. Later, let your child point to recognizable pictures and try to name them. Then move on to nursery rhymes, which have rhythmic appeal. Progress to predictable books (such as Bear Hunt) that let kids anticipate what happens. Your little one may even start to memorize favorite stories.
Use everyday situations to reinforce your child's speech and language. In other words, talk your way through the day. For example, name foods at the grocery store, explain what you're doing as you cook a meal or clean a room, point out objects around the house, and as you drive, point out sounds you hear. Ask questions and acknowledge your child's responses (even when they're hard to understand). Keep things simple, but never use "baby talk."
Whatever your child's age, recognizing and treating problems early on is the best approach to help with speech and language delays. With proper therapy and time, your child will likely be better able to communicate with you and the rest of the world.