pay off有被动语态，但要加be动词，即be paid off。pay off可以用作主动也可以用作被动，作主动时以人为主语，作被动时以物为主语，中文含义有“偿清”、“还清欠…的钱”、“成功”、“赢利”。
1、It would take him the rest of his life to pay off that loan.
2、Sandra was determined to become a doctor and her persistence paid off.
3、I can guarantee that he will pay off the debt.
4、He had struggled to pay off creditors but couldn't fend them off any longer.
5、They doubted whether all this work would pay off.
6、They have loans, bills, a mortgage to pay off, retirement to save for.
7、You can pay it off or make a minimum repayment.
8、If my investment doesn't pay off I'll feel used.
9、I believe that hard work and determination pay off.
10、Still, the company expects its investment will pay off.