 You can introduce new words to a child when you speak to them. Instead of using a common word to describe something, you can use a similar word that might be new to the child. For example, instead of saying that a tree is big, you could say that it is large or huge or giant or enormous. Or, instead of saying that the food is good, you could say that it is tasty, yummy, delicious, or wonderful. By doing this, you will help the child learn new words for describing things.