''what's happened to you?''the old man said to me为什么HAPPEN要加ED如果是过去式为什么要用IS,WAS是不可以缩写的吧

问题描述:

''what's happened to you?''the old man said to me
为什么HAPPEN要加ED
如果是过去式为什么要用IS,WAS是不可以缩写的吧

what has happened to you
完成时态,用has