I don’t know _______ they have passed the exam.
问题描述:
I don’t know _______ they have passed the exam.
这里答案是if/whether,但是我觉得when跟how填进去也说得通啊.请问为什么不能填when跟how、?
答
因为when/how必须是指当时和如何.所以后面一定要接过去时,而不是现在完成时.也就是说:When/How did they have passed the exam?从句中应该改为陈述语序,那请问这个如果是用when/how,要怎么写完整的句子?如果用when/how 应该是:I don’t know when/how they passed the exam. (不好意思,刚才解释对了却打错了,必须是过去时。)