副詞可以充當時間狀語嗎

副詞可以充當時間狀語。

例如：

immediately， directly， instantly，early，late，before，later，yet

already，just，sometimes，often，usually，once，twice、three times...

I came immediately you called.

Directly I walked in the door I smelt smoke. 

We will visit the Great Wall tomorrow.

Sometimes I get up early.

The workers usually have lunch at the factory.

Take this medicine twice a day.