陳述部分帶有needn't時(shí),附加問句部分通常仍用need
You needn't go yet,need you?
這里也可以用must作"有必要"解
He needn't do that,must he?
陳述部分帶must表"義務(wù)"時(shí),附加問句部分通常仍用must
You must work hard next term,mustn't you?
You mustn't walk on grass,must you?
但當(dāng)作"有必要"解時(shí),隨后的附加問句部分即可用"mustn't"也可 用"needn't".
You must go home right now,mustn't you?/needn't you?
當(dāng)表"一定""想必"解時(shí),附加問句仍用must
He must be very tired,mustn't he?
總結(jié),用什么要看意思,不管是must還是need,用本身就沒錯(cuò)
另外,整句表示"詢問請求"之意,附加問句用may
I want to open the window,may