题目内容：

if that's what happened中what做什么成分?可以删掉吗?

优质解答

可以.if that's happened可以理解成 if that has happened.不过中文意思就变了.
if that's what happened：如果这就是所发生的.what 是后面表语从句的引导词,做happened的主语
if that has happened：如果那个发生了.