2015年6月的英语四级已经告一段落，随之而来的就是12月份的英语四级备考任务了。暑假期间时间充裕，除了玩耍娱乐，考生也要稍稍抽出一部分时间来为下半年的考试稍作准备。下面是英语四级语法的基础内容，赶紧复习吧!

　　动词(时态,语态,用法,省略,一致性等)

　　时态

　　1)现在完成进行时态 (have/has been + -ing 分词构成): 动作或状态从过去某时开始,继续到现在,可能继续下去,也可能刚刚结束.

　　I’ve been writing letters for an hour.

　　I’ve been sitting in the garden.

　　2)过去完成进行时(由had been + ing分词构成): 过去某个时刻以前一直在进行的动作

　　I’d been working for some time when he called.

　　We had been waiting for her for two hours by the time she came.

　　3)将来完成进行时: 将来某个时刻以前一直在进行的动作.

　　By next summer, he will have been working here for twenty years.

　　In another month’s time she’ll have been studying here for three years.

　　4)将来完成时(由shall/will have + 过去分词构成): 将来某时已发生的事.

　　I shall have finished this one before lunch.

　　They’ll have hit the year’s target by the end of October.