有多种说法,我个人比较习惯这种——
He hasn't paid me back yet.
不过比较书面化的也许是你想要的——
He hasn't paid back the money to me.
现在回答你的另几个问题:
1.当然要用to这个介词,因为在这里含义是“给谁谁谁”的意思。
2.其实你一定要用 pay the money back这样的顺序也可以,不过这句话就要这样说——
He hasn't paid the money back to me. 不论如何后面介词要用to 不过这样搭配会比较奇怪。
.
pay back the money
还清这笔钱
pay the money back
还钱
he has not paid the money back .
He hasn't paid the money back to me yet.
pay the money back
back不是pay的词组。