There are three main reasons why children may make errors when speaking. They may be tired and may find it hard to pay attention. Alternatively, they may be applying a Chinese language pattern to English or they may be confused about how to use a new word or grammatical structure.
Errors are a natural and necessary part of the learning process. They can also be a positive sign. Errors provide information about what progress the class is making. If many children are making the same error, you may need to review that part of the lesson. Errors may actually show learning. It is natural for language learners to overgeneralise rules. It is like an experimental process: We try something to see if it works. If it doesn’t work, we try something else until we get it right.
The teacher does not need to correct every error. More correction does not lead to fewer errors. If the teacher corrects too much, it could have a negative influence on the children’s willingness and motivation to participate in the class.
Instead of correcting errors for them, you can encourage children to correct their own errors. You can give a surprised look when you hear an error, or shake your head and wait for the student to try again. Hand gestures can also be effective. At the end of the lesson, you can write up some mistakes on the board and ask the children to correct them. All of these methods help children think about the mistakes they made, and help them remember next time.