大学英语六级基础语法知识：时态
在大学英语六级考试中，单独考察六级语法的题型不多，但是语法知识点却贯穿整张试卷，下面是小编为大家整理的大学英语六级基础语法知识：时态，希望可以为大家带来帮助。
1. 现在完成时、过去完成时以及将来完成时之间的区别
1) 现在完成时：
① 构成：have / has +过去分词
② 语法意义及要点：
A. 现在完成时表示一个过去开始的状态或动作持续到现在并可能继续持续下去，常同表示一段时间的状语连用。如so far, up to now, since, for a long time等。
--He has worked as a teacher for many years.
--Up till now, nothing has gone wrong.
B. 现在完成时表示一个过去发生的对现在仍有影响的动作或事件。常与不确定的过去时间状语连用，如yet, just, before, recently等;也同表示频度时间状语连用，如often, ever, never, sometimes, several times等;还可同包括现在时间在内的时间状语连用，如now, today, this morning等。但不能同特定的过去时间状语连用(last year , in 1997等)。
--I ha ……此处隐藏615个字……iven
Shall we be asked to attend the opening ceremony?
过去将来时：would be＋given
The news would be sent to the soldier's mother as soon as it arrived.
现在进行时：am/is/are being＋given
The machine is being repaired in the workshop. The fifth generation computers, with artificial intelligence, are being developed and perfected now.
过去进行时：was/were being＋given
The feast was being prepared when the birds arrived in the sky
现在完成时：has/have been＋given
Swift progress has also been made in culture and education.
过去完成时：had been＋given
The huge bridge had been damaged before the World WarⅡ.
将来完成时：will/shall have been＋given
The book will have been published by the end of next month.
