用could开头的问句

yes,I could.No,I couldn't.因为could是can的委婉形式,所以用法相同.

应用can来否定,No,I can't.

can,回答里不用could

肯定回答用 yes, can 否定回答用 no, ..can't.

-May -Yes,you may/you can(No,you can't) -Must -Yes,you must(No,you needn't/you don't have to) -Could -Yes,you can(No,you can't)

还是can ,因为以could 开头的一般疑问句表示语气更加委婉礼貌,不表示股过去的时态,所以回答仍然用can

Must I finish it today? No, you needn't. / don't have to . You can finish it tomorrow.may i go home now? no, you can't. yes ,you may.could you please open the door ? yes ,of course .

No,you couldn't.

could 表示委婉语气,通常当你对别人提出请求时,会用could you please..?could you mind?这些都能显示出你的委婉和客气.could 和can 没有时间的差别,不是说could 表示过去而can表示现在.can 也可以用于疑问句开头,只是没那么委婉,但还是可以的.

是的 特殊疑问句都是以特殊疑问词开头的