快速复习动词时态之法,

快速复习动词时态之法,
快速复习动词时态之法,

快速复习动词时态之法,
动词时态是语法测试中一个很重要的方面.要掌握动词时态,必须弄清每一时态的基本时间概念及基本用法；更要弄清句中以什么时态为基点,从而理解一个时态与另一个时态在同一个句子中的交叉使用情况.
（1） 句中时态以现在时间为基点 句中时态以现在时间为基点,那么句子中可以相互搭配的时态形式通常有：一般现在时、 现在进行时、一般将来时、一般过去时、现在完成时、现在完成进行时等,但就时态的测试重点多在于现在完成时.
如：You should have put the milk in the ice-box; I expect it ____ undrinkable by now.
A) became B) has become C) had become D) become
句中第二分句中的时态基点为现在时（谓语动词expect）,句中时间短语"by now"表示"到现在为止",暗示动作已完成,故答案为（B）.
（2）句中时态以过去时间为基点,句中可相互搭配的时态通常有：一般过去时、过去进行时、过去将来时、过去完成时、过去完成进行时等.
如：Whenever we visited them,they ____ television.
A) have watched B) watch C) had watched D) were watching
句子时态的基点为过去时间,那么在句中与之相搭配的时态,从四个选择项的形式来看,有（C）和（D）.再根据whenever的词意,可以判断（D）为正确答案.
（3）主要时态的时间状语提示词
现在完成时：so far,by now,up to now,for,since,recently,lately,in the past few…,during the last few…,etc.
过去完成时：by the end of＋过去的时间,by then,up to then,etc.
将来完成时：by the end of ＋将来的时间
在四级语法结构测试题中,以动词时态为测试对象的大多是对现在完成时、将来完成时、过去完成时的测试.
例3 By the end of this month,we surely ____ a satisfactory solution to the problem.
A) have found B) will be finding C) will have found D) are finding
答案是（C）.这里由by引起的时间状语表示到将来某个时间为止,因此句子的谓语动词需用将来完成时.
例4 We ____ our breakfast when an old man came to the door.
A) just have had B) have just had C) just had D) had just had
答案是（D）.主句的动作发生在从句之前,从句的时态是过去时,因此主句应用过去完成时.
1．动词时态
1) By the end of this year all but two people ____.
aa?have left?will leave?will be leaving?will have left
2) She will come to call on you the moment she ____ her work.
aa?has finished?finished?had finished?will finish
3) You will hardly believe it,but this is the third time tonight someone ____ me.
aa?telephoned?has telephoned?telephones?should telephone
4) The company ____ a rise in salary for ages,but nothing has happened yet.
aa?promised?is promised?is promising?has been promising
5) Is it likely that the scientists ____ a cure for cancer by the year 2050?
aa?will be discovering?are discovering?will have discovered?have discovered
6) This is the second time I ____ your beautiful country.
aa?had visited?visited?am visiting?have visited