1 He is not （what） he was等于He is not （what） he used to be 吗2

1 He is not （what） he was等于He is not （what） he used to be 是正确的,可以这么说.句意：他不是以前的他了.（外表、性格等已经变了）
2 这两个括号内的内容填的对不对?完全正确.两个都是由what连接的表语从句.
3 who是主格也是宾格吗?who是主格,口语中随便一些有时宾格也用,但是紧跟在介词后就只能用whom.如：
Who/Whom do you like best?
Who/Whom would you like to go with?
With whom would you like to go?(Who不能用)