let alone片語

更不用說、更別提、何況多用於否定句

He can't even boil an egg, let alone cook dinner.

他連水煮蛋都不會，更不用說做晚飯了。

別打擾、不去管可拆開

Let him alone for now; he needs time to think.

現在先別打擾他，他需要時間思考。