Who would you ask for help if you were robbed

首先,这句话的意思是当你被抢劫的时候你会向谁求救?
其次,这句话如果是who would you aks for help if you were robbed?可以看做是一个补语从句,也就是说,去掉 if you were robbed 这句话也成立；前面的who .是一个特殊疑问句,类似于 what are you doing这类常见简单句型.
最后,这句话不能那么改,是个错误的句子.一定要用的话,who应该改成when,不过这时的句意已经和题目的句子发生改变,变为：当你被抢劫时你会求救吗?
希望有所帮助^^