第1个回答 2009-04-24
Unit 9 Have you ever been to an amusement park?
重难点详解
1. Have you ever been to an amusement park? 你曾经去过游乐场吗?
Have you ever been to…? 意为“你曾去过……吗?”其中have been to是现在完成时的一种用法。ever可用于疑问句中,表示“曾经”,常与现在完成时连用。如:
Have you ever been to Wuhan? 你曾经到过武汉吗?
Have you ever spoken to a foreigner? 你曾和外国人谈过话吗?
【特别提醒】have(has) been to表示曾经去过,但现在不在那个地方;have(has) gone to则表示已去了某个地方,现在也许在那里,也许在途中。如:
They have been to Shanghai. 他们曾去过上海。(现在不在上海)
They have gone to Shanghai. 他们已去了上海。(现在也许在上海,也许在途中)
2. They are going to take the subway. 他们打算乘坐地铁。
“take+the+交通工具”用于表示“乘……”,相当于“by+交通工具”。如:
It will save you a lot time if you go there taking the subway. 如果你坐地铁去那里,可以节省很多时间。
3. On the one hand, more than three quarters of the population are Chinese. 一方面超过四分之三的人是华人。
(1)three quarters指“四分之三”。quarter在这里指“四分之……”。half可以表示“二分之一”,英语中的序数词都具有“……之……”的意思。用他们表示分数的分母时,常用基数词表示分子。另外,如果表达分子的数量超过一,那么该序数词用复数。如:
one fifth五分之一;two thirds三分之二;seven tenths十分之七
【特别提醒】表示“二分之一”和“四分之一”因为已经有了约定俗成的用法,所以一般不用one second和one fourth表达。
(2)population可以用于表示“人口数目”,指the number of people也可以表示“人民”,指people。所以,当population作为主语出现时,应根据它所指代的具体意思来确定谓语动词的单复数 形式。作前一种意思解释时,谓语动词用第三人称单数。作后一种意思解释时,其后谓语动词用复数。如:
The population here is very small, so the people here are leading a quiet life. 这里的人口很少,所以这里的人们都过着一种安逸的生活。
语法
现在完成时
现在完成时由主语+have/has+过去分词构成。其主要用法如下:
1. 在未指明具体时间的情况下,现在完成时动词通常可以表示在说话之前已经完成,而后果或影响至今仍存在的动作。如:
The concert has started. 音乐会已经开始。
I have had breakfast. 我已吃过早饭。
注意:have gone to 和 have been to 在意义上有区别。如:
He has gone to Hong Kong. 他到香港去了。(他已前往香港,或在途中,或已到达。说话人暗示他现在不在现场。)
He has been to Hong Kong.他曾到过香港。(说话人认为他过去到过香港,现在已不在该地。言外之意他对香港有所了解。)
2. 现在完成时动词可以表示开始于过去持续到现在(也许还会继续进行下去)的动作或状态。如:
I have studied English since last year. 我从去年开始学习英语。
She has lived in Beijing for five years. 她住在北京已经五年了。
注意:come, go , leave, arrive, buy, lose, receive, join, die, bury 和marry 等动词所表示的动作是一时的,不能延续的,故不能与for …,since …等开头的表示一段时间的状语连用。不过,这些词用于否定句则可以与表示持续的时间状语连用,即动作的不发生是可以持续的。
如:
不能说:*He has come to Beijing for two years.
*He has bought that book for three weeks.
*He has joined the Army for one and a half years.
*His grandma has died for nine months.
* I have received his letter for a month.
可以说:
He has been in Beijing for two years.
He has had that book for three weeks.
He has been in the army for one and a half years.
His grandma has been dead for nine months.
I haven't received his letter for almost a month.
或者:
It is two years since he came to Beijing.
It is three weeks since he bought that book.
It is one and a half years since he joined the Army.
It is nine months since his grandma died.
3. 现在完成时把过去的动作和现在的结果联系起来,一般过去时只限于表示过去的动作本身,与现在的结果无关。现在完成时与一般过去时在意义上的区别举例如下:
I have cleaned my room. (My room is clean now.) 我已经打扫过我的房间了。
I cleaned my room last week. (I did it in the past.) 我上周打扫了我的房间。
Father has gone to Amoy. (He went to Amoy and he is not here now.) 爸爸已经去厦门了。
They have bought a dictionary. (They bought a dictionary and they have it now.) 他们买了一本字典。
注意:现在完成时不能和明确指出时间的状语(如:yesterday, last, year, in 1976, two days ago, just now, when she came in 等)连用,但可以和不明确指出时间的状语(如:already, yet, ever, never, sometimes, always, often, before, once, twice, recently, lately等)连用;也可以和表示包括现在在内的时间状语(如:today, this morning, this week, this year等)连用。例如:
She has already finished her work.她已经把工作做完了。
I haven’t read the story yet. 我还没读过这个故事。
Have you met him before? 你从前曾见过他吗?
Lily has always been a good student. Lily一直是个好学生。
比较:
I have seen him this morning .我上午看见他了。(说话时在上午)
I saw him this morning.今天上午我遇见了他。(说话时可能是下午或者晚上)
It has been cold this winter. 今天冬天一直很冷。(说话时仍是冬天)
4. 现在完成进行时和现在完成时都可以表示“从过去开始一直持续到现在”这一概念,有时两者可以互相代用,但前者多用于口语。在含义上如着重表示动作的结果时,多用现在完成时;如着重表示动作一直在进行,即动作的延续性时,则多用现在完成进行时。一般不能用于进行时的动词也不能用于现在完成时行时。
比较:
I have waited for him for many times. 我等他等了好几次了。
I have been waiting for him for an hour. 我等他等了一小时。
He has drunk six cups of coffee. 他喝了六杯咖啡。
He has been drinking coffee. 他一直在喝咖啡。
5. 现在完成时的用法:
(1)现在完成时说明至目前为止已发生的动作或已有的经验。
(2)现在完成时通常与下列词语连用:yet, already, by this time, just , ever, never, before, several times, since, up to now, so far, recently, lately, for a long time
(3)have been 表示经验,即“曾经过去”。
(4)have gone 表动作的完成,表示“已经到……去了”,因此只可用于第三人称;在面对面谈话时,不可用于第一、二人称。如:
-Have you ever been anywhere even for a trip?
-I have been to Long Island.
Mr. Smith has gone to America, so he is not here.
-How long have you been here?
-I’ve been here since three weeks ago.