None of the students (understand)what he (say)did they

问题描述:

None of the students (understand)what he (say)did they

None of the sutdents understood what he said, did they?

None of the students understood what he said, did they?

None of the students understood what he said,did they?
一般来讲none of +人即使人用复数形式,其后面的谓语动词也一定用单数.但在此句中,后面用来表达反义疑问的did they,表明了此句的时态为过去时,从而被反义疑问的understand即应用过去时understood,同样understand的内容是“他说的”也是已经说过的,所以也用过去式.