英语四、六级考试语法精要解析:时态3
分类: 考研
时间: 2019-04-09 13:14:52
作者: 全国等级考试资料网
3. 时态的呼应
时态的呼应又称时态一致(Sequence of Tenses),指的是某些从句里的动词谓语时态必须和主句里的时态保持一致。
如果主句里的谓语动词是过去时态(过去时或过去完成时),那么从句的谓语动词时态也相应地要用过去时。时态的呼应主要发生在间接引语和宾语从句中,但其他从句有时也存在时态一致的问题。
--He explained that he had learned Chinese for many years.(现在完成时变为过去完成时)
--He said he had been collecting materials on that subject for a long time.(过去进行时变为过去完成进行时)
--He told me that they would have completed that project by the end of the year.(将来完成时变为过去将来完成时)
虽然主句用了过去时等,如果从句表示的是科学真理、客观事实或某人(物)的经常性特点时,其时态可以不必遵守时态呼应的规则而仍用一般现在时。
--Galileo proved that the earth revolves round the sun.
--The teacher told the students that knowledge is power.
如果从句中有一个表示绝对过去时间的状语,就不必把一般过去时变为过去完成时。
--He said that he joined the Red Army in 1933.