用法：pay off后一般接表示钱款、贷款的名词。
例句：It may take thirty years for them to?pay off?the mortgage. (2013年12月四级)
他们可能要过三十年才能把房贷还清。
结构分析：It是形式主语，may take是谓语，?thirty years是宾语，for them to?pay off?the mortgage是真正的主语，其中for them是逻辑主语。
"pay off"的意思都是最终取得成功，在剑桥词典中的英文解释为"If something you have done pays off, it is successful"。
"pay off"还有另一个常用的意思为“付清” - "the final payment of a debt"，例如"It would take him the rest of his life to?pay off?that loan." - “还清那笔贷款将耗尽其余生”。两种用法都很常见，实际生活中我们可以根据语境来判断具体的意思。
扩展资料
All her hard work?paid?off?in the end, and she finally passed the exam.
她所有的努力取得了成功，她最终通过了这个考试。
Sandra was determined to become a doctor and her persistence paid off.
Sandra立志要成为医生，最终她坚持不懈的努力收获了成功。