是這樣的,needn't do 和 don't need to do 兩者有些差別.
就像needn't have done 和 didn't need to do 一樣.
從用法上,前者是情態(tài)動(dòng)詞,后者是實(shí)義動(dòng)詞.
從意義上,前者暗示已經(jīng)做了,有“本不需要”的意思,后者暗示還沒有做,就是純粹地“不需要”.
如：You needn't do the housework.(說話時(shí)你已經(jīng)做了家務(wù))
You don't need to do the housework.(說話時(shí)你尚未做家務(wù)