请问what happened?这个问句成不成立?怎么可以一个助动词都没有呢?

请问what happened?这个问句成不成立?怎么可以一个助动词都没有呢? what happened to you?是问句,怎么没有助动词? what happened这个句子对吗 为什么 what has happened.这个句式有错吗 what happened 和what has happened 有什么区别么请问 问句,what happened ,答句,about to pass out 这两句怎么翻译什么意思 请问What do you think happened to they? What had happened?What had happened?What had happened? 请问这个反问句怎么改 是What happened 还是what’s happened what happened=what's happened吗? what happened to 和what happened general statement of what happened when请问这句短语如何翻译?尤其是what happened when这一部分怎么讲? 在这个句子中what happened 作什么成分?例句是：Please give a full account of what happened yesterday. what happened at last? what happened on What Happened to Us what happened then