为什么有时happen用助动词进行提问,而有时则不用?如：What will happen...What happene

为什么有时happen用助动词进行提问,而有时则不用?如：What will happen...What happene what happen为什么没有助动词 为什么what直接加happen,而how加助动词did加happen what will happen next? what will happen? what will happen then what will happen without trees what will these things happen what will happen tomorrow?中文? What will happen without electricity? What happen what happened 为什么不可以用 what did happen