Correção de texto "We all know we change after some years"

We all know we change after some years. When we turn adults, we do not think in the same way as when we were a child. We change our habits, hobbies and concerns. We get mature. We start to act in a different way.
When you are teaching English as a second language, you constantly face different age level classes. You can face kids, teens or adults.
During your experience as a teacher, you are going to find out that, each age level has its own characteristics.