tacitly：なんとなく

Who do you think is a good teacher?
This is an eternal theme for me until I quit teaching English.

There seems to be various kinds of factors which are included in "a good teacher".

Rectnly I realized one thing.

What I think everyone already knows is not always what they know in reality.
They tacitly understood English grammar points to some extent,
but they couldn't explain certain grammar crealy and make use of this grammar.

So as a teacher, I noticed that I should dare to explain what might be already
known by my students or not new for them in order to confirm how much they understood it and make up for the lack of their knowledge if necessary.