Before the age of 3, it is a critical period for children's language development. If children can't speak at the age of 2-3, language development is actually very slow. If other problems such as autism or brain development are ruled out, it is pure language retardation, and he has no social problems. This kind of child needs a lot of stimulation from the environment. Of course, they must first do a good job in listening and brain examination. After all the organic problems are eliminated, it is necessary to train children, provide them with a lot of environmental stimuli, and interact and communicate with them. For example, when a child is playing, you can tell him that he is playing. There is a one plus one principle, that is, if the child already knows two words, or he doesn't know a word, we will say one or two words for him. Because he is playing with a car, that is, a car. Every time he pushes a car, you say a car. Maybe a dozen times later, he also tells you a car. Then after he says a car, you start talking about a cart. Then after he pushes it, he says to push the car quickly, which becomes three words and four words, and then slowly add a word for him to tell you. But it doesn't mean that it's all added at once. If it's so long, the child can't understand it at all, so he can't tell you. But if you add more slowly, he may talk more. Besides, we need to get along with many friends. We will find that children may not talk much when playing with adults, but when playing with young children, other children are more likely to talk when talking. It's good to have an environment. If there is no such environment at home, it is recommended to go to early childhood classes, or to kindergartens and nurseries, so that children can have many opportunities to contact other children.