Difference between to reflect and to express in Korean
반성하다·표현하다

반성하다to reflect
(반성하다) means to think carefully about your mistakes or bad behavior and feel sorry about them. You use it when you look back at what you did and want to do better next time. It is common after making a mistake at home, at school, or with other people.

표현하다to express
표현하다 means "to express." You use it when you show your feelings, thoughts, or ideas with words, your face, writing, or actions. It is often used for things like feelings, opinions, and thanks.
The difference
to reflect (반성하다) and to express (표현하다) are nearby Korean vocabulary items learners often meet together. Use “to reflect” when (반성하다) means to think carefully about your mistakes or bad behavior and feel sorry about them. You use it when you look back at what you… Use “to express” when 표현하다 means "to express." You use it when you show your feelings, thoughts, or ideas with words, your face, writing, or actions. It is oft…