Question

I will tell you all that he said .all that可否换成that

Answer 1

语法没问题.这里 that 可以省略,读起来会更顺.

I will tell you all that he said

我会告诉你他说过的所有话.

不行,因为直接宾语 all 是先行词,后面的定语从句修饰all.

可以改成 everything 之类.