今天为大家推送的是四六级，一起来看看吧！英语四六级语法（46）比较过去时与现在完成时
1)过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作;现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。
2)过去时常与具体的时间状语连用，而现在完成时通常与模糊的时间状语连用，或无时间状语。
一般过去时的时间状语:
yesterday, last week，…ago, in1980, in October, just now, 具体的时间状语
共同的时间状语:
this morning, tonight,this April, now, once，before, already, recently，lately
现在完成时的时间状语
for, since, so far, ever, never, just, yet,till / until, up to now, in past years, always,
不确定的时间状语
3)现在完成时可表示持续到现在的动作或状态，动词一般是延续性的，如live, teach, learn, work, study, know.
过去时常用的非持续性动词有come, go, leave, start, die, finish, become, get married等。
举例：
I saw this film yesterday.
全部倒装
全部倒装是只将句子中的谓语动词全部置于主语之前。此结构通常只用与一般现在时和一般过去时。常见的结构有：
1) here, there, now, then, thus等副词置于句首, 谓语动词常用be, come, go, lie, run。
There goes the bell.
Then came the chairman.
Here is your letter.
2) 表示运动方向的副词或地点状语置于句首，谓语表示运动的动词。
Out rushed a missile from under the bomber.
Ahead sat an old woman.
注意：上述全部倒装的句型结构的主语必须是名词，如果主语是人称代词则不能完全倒装。
Here he comes.Away they went.
(强调看的动作发生过了。)
I have seen this film.
(强调对现在的影响，电影的内容已经知道了。)
Why did you get up so early?
(强调起床的动作已发生过了。)
Who hasn't handed in his paper?
(强调有卷子，可能为不公平竞争。)
She has returned from Paris.
她已从巴黎回来了。
She returned yesterday.
她是昨天回来了。
He has been in the League for three years.
(在团内的状态可延续)
He has been a League member for three years.

(是团员的状态可持续)
He joined the League three years ago.
( 三年前入团，joined为短暂行为。)
I have finished my homework now.
---Will somebody go and get Dr. White?
---He's already been sent for.
句子中如有过去时的时间副词(如 yesterday, last, week, in 1960)时，不能使用现在完成时，要用过去时。
(错)Tom has written a letter to his parents last night.
(对)Tom wrote a letter to his parents last night.