I 'll tell u [all which] he told me last week

I 'll tell u all that he told me last week
这是句子是定从,由于all是不定代词,所以只能用that引导,不用which,其次,that在从句充当宾语,所以可以省略.
这句话的意思是 我将告诉你他上周告诉我的所有事.
I'll tell u what he told me last week.
这个句子是宾语从句,what从句是做tell的宾语,what不能省略,做told的宾语.
我将告诉你他上周告诉我的事情.