7.过去完成时的用法 1) 过去完成时由“had + 过去分词”构成。过去完成时的动作表示过去某一时刻或某一时刻或某一动作之前完成的动作或状态。句中常用by, before, until, when 等词引导的时间状语。 By the end of last year we had built five new houses. I had learnt 5000 words before I entered the university. 2)过去完成时的动词还可表示过去某一时刻之前发生的动作或状态持续到过去某个时间或持续下去。Before he slept, he had worked for 12 hours. 8.过去将来时的用法 过去将来时表示从过去的某个时间看来将要发生的动作或存在的状态。过去将来时由 “should 或 would + 动词原形” 构成。第一人称用should, 其他人称用would. They were sure that they would succeed. 9.现在完成进行时的用法现在完成进行时由 “ have (has)+ been + 现在分词”构成,表示现在以前一直进行的动作。有些动词(work, study, live, teach 等) 用现在完成时与用现在完成时意思差不多。 I have worked here for three years. I have been working here for three years. 但多数动词在这两种时态表示不同意思 I have been writing a letter. 注意:表示短暂动作的动词(finish, marry, get up, come, go 等)不能用这种时态。 (二) 动词语态 1. 当句子的主语是动作的执行者时, 谓语的形式叫主动语态。句子的主语是动作承受者时,谓语的形式叫被动作语态。被动语态由助动词be + 过去分词构成,时态通过be 表现出来。 1) 一般现在时:You are required to do this. 2) 一般过去时:The story was told by her. 3) 一般将来时:The problem will be discussed tomorrow. 4) 现在进行时:The road is being widened. 5) 过去进行时:The new tool was being made. 6) 现在完成时:The novel has been read. 7) 过去完成时:He said that the work had been finished. 8) 过去将来时:He said that the trees would be planted soon. 2. 一些特殊的被动结构 1) 带情态动词的被动结构:The problem must be solved soon. 2) 带不定式的被动结构:The room is going to be painted. The homework needs to be done with care. (责任编辑:admin) |