what's 可以是what is 的缩写，也可以是what has 的缩写;具体判断的时候要看语境。一招分清：what's 是 what is 还是 what has
记住看后面紧跟的单词就行，超好分辨。
1. what's = what is
后面跟：名词 / 形容词 / 介词短语 / 现在分词 (ing)
What's this? (名词)这是什么?
What's wrong? (形容词)怎么了?
What's in the box? (介词短语)盒子里有什么?
What's happening? (ing 形式)正在发生什么?
2. what's = what has
后面跟：过去分词(动词 ed / 不规则分词)
What's happened? 发生了什么?
What's gone wrong? 出了什么问题?
What's been done? 已经做了什么?
极简口诀
后接 ing / 名词 / 形容词 → what is
后接过去分词 → what has
