She had learned some English before she came to the institute.　她在来学院之前已学过一些英语。 He said that he had been abroad for 3 years. 他说他在国外待了3年了。 2.表示从过去某一时间开始，一直延续到过去的另一时间的动作，常用的时间状语有：by then，by that time，until，by the end of，before 2011，by the time＋句子等。