Correcting a language learner
Just as with the parent correcting the child, correcting a language learner has a limited effect. You cannot possibly have all your mistakes corrected as you progress to fluency. You have to notice these mistakes yourself. Corrections can help make you more attentive to the language. But then it should be in the form of a written correction after a discussion, and not in the form of an interruption while communicating, in my view.