could后面不是要用动词原形吗,为什么happened不是happen??
Could you tell me (what happened 是宾语从句 谓语是tell 跟 could 有啥联系?)
从句中的时态怎么是要用过去式呢?
该句话变成陈述句是 you could tell me what happened。
could的后面是跟的tell 动词原形啊