i owe him but you

I owe you (one) INFORMAL
used as a way to thank someone for helping you and showing that you will do something for them in the future:
Thanks for the help, Bill - I owe you one.

您的语法是不对的
我欠他的而不是你的：I owe him, not you. 或者复杂点 He is the person whom I owe but you are not.

补充剑桥的解释。在剑桥例句中没有出现not 可以省略的情况.查阅OWE后也没有发现您给出的句子。
but (DIFFERENCE) Show phonetics
conjunction
used to introduce an added statement, usually something that it different from what you have said before:
She's very hard-working but not very imaginative.
This is not caused by evil, but by simple ignorance.
The play's good, but not that good - I've seen better.
I'm sorry, but I think you're wrong when you say she did it deliberately.
Call me old-fashioned, but I like handwritten letters.
I can understand his unhappiness. But to attempt suicide!
"She said she's leaving." "But why?"
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