三张图看懂现在完成时中“不确定的过去”

口语写作中12种的时态使用，是让很多人头疼的一件事。

12种时态的变化规则背下来倒是不难，但是难的事情在：到底应该用哪种？

上次图解了一般现在时，今天再给大家分享：什么时候应该用现在完成时

USE 1 Unspecified Time Before Now

We use the Present Perfect to say that an action happened at an unspecified time before now. The exact time is not important. You CANNOT use the Present Perfect with specific time expressions. We CAN use the Present Perfect with unspecific expressions.

现在完成时可以表示现在之前，不确定的一个时间，具体的时间是过去的什么时候不重要。

甚至不可以表示明确的过去的时间，例如：yesterday, one year ago, last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc.

不确定的过去是可以的: ever, never, once, many times, several times, before, so far, already, yet, etc.

举例:

• I have seen that movie twenty times.

• I think I have met him once before.

• There have been many earthquakes in California.

• People have traveled to the Moon.

• People have not traveled to Mars.

• Have you read the book yet?

• Nobody has ever climbed that mountain.

• A: Has there ever been a war in the United States?

  B: Yes, there has been a war in the United States.

再解释解释？

不确定的时间这个概念可能有点晕，下面再来几个具体的例子。

TOPIC 1 Experience

You can use the Present Perfect to describe your experience. It is like saying, 'I have the experience of...' You can also use this tense to say that you have never had a certain experience. The Present Perfect is NOT used to describe a specific event.

可以说有过某种体验，从来没有过某种体验。不能描述某一次特定的事件。

例子:

• I have been to France.

  反正是去过法国，去过一次还是好几次无所谓。

• I have been to France three times.

  也可以说总共去过几次。

• I have never been to France.

  表示从来没经历过。

• I think I have seen that movie before.

• He has never traveled by train.

• Joan has studied two foreign languages.

• A: Have you ever met him?

  B: No, I have not met him.

TOPIC 2 Change Over Time

We often use the Present Perfect to talk about change that has happened over a period of time.

现在完成时还可以表示一段时间以来的变化。

Examples:

• You have grown since the last time I saw you.

• The government has become more interested in arts education.

• Japanese has become one of the most popular courses at the university since the Asian studies program was established.

• My English has really improved since I moved to Australia.

TOPIC 3 Accomplishments

We often use the Present Perfect to list the accomplishments of individuals and humanity. You cannot mention a specific time.

现在完成时还可以表示某人/某一群人的成果。当然还是不能提及特定的时间。

Examples:

• Man has walked on the Moon.

• Our son has learned how to read.

• Doctors have cured many deadly diseases.

• Scientists have split the atom.

TOPIC 4 An Uncompleted Action You Are Expecting

We often use the Present Perfect to say that an action which we expected has not happened. Using the Present Perfect suggests that we are still waiting for the action to happen.

现在完成时还可以表示期待的事情还没有发生，依然在等待。

Examples:

• James has not finished his homework yet.

• Susan hasn't mastered Japanese, but she can communicate.

• Bill has still not arrived.

• The rain hasn't stopped.

TOPIC 5 Multiple Actions at Different Times

We also use the Present Perfect to talk about several different actions which have occurred in the past at different times. Present Perfect suggests the process is not complete and more actions are possible.

现在完成时还可以表示过去发生的事情没有完成，还可能要继续。

Examples:

• The army has attacked that city five times.

• I have had four quizzes and five tests so far this semester.

• We have had many major problems while working on this project.

• She has talked to several specialists about her problem, but nobody knows why she is sick.

Time Expressions with Present Perfect

When we use the Present Perfect it means that something has happened at some point in our lives before now. Remember, the exact time the action happened is not important.

现在完成时不关心到底是在过去的哪个时间完成的。

Sometimes, we want to limit the time we are looking in for an experience. We can do this with expressions such as: in the last week, in the last year, this week, this month, so far, up to now, etc.

现在完成时可以表示在过去某个时间段，但是不确定在哪个时间点。

Examples:

• Have you been to Mexico in the last year?

• I have seen that movie six times in the last month.

• They have had three tests in the last week.

• She graduated from university less than three years ago. She has worked for three different companies so far.

• My car has broken down three times this week.

NOTICE

'Last year' and 'in the last year' are very different in meaning. 'Last year' means the year before now, and it is considered a specific time which requires Simple Past. 'In the last year' means from 365 days ago until now. It is not considered a specific time, so it requires Present Perfect.

'Last year' 和 'in the last year' 截然不同。

'in the last year'是不确定在去年的具体哪个时间，是过去完成时。

'Last year' 是确定在去年，是过去时。

Examples:

• I went to Mexico last year.

  I went to Mexico in the calendar year before this one.

• I have been to Mexico in the last year.

  I have been to Mexico at least once at some point between 365 days ago and now.

USE 2 Duration From the Past Until Now (Non-Continuous Verbs)

With Non-Continuous Verbs and non-continuous uses of Mixed Verbs, we use the Present Perfect to show that something started in the past and has continued up until now. 'For five minutes,' 'for two weeks,' and 'since Tuesday' are all durations which can be used with the Present Perfect.

现在完成时还可以表示从过去某个时间点开始，持续了一段时间直到现在。

Examples:

• I have had a cold for two weeks.

• She has been in England for six months.

• Mary has loved chocolate since she was a little girl.

读到这里可能你想吐个槽

告诉我“两周前”，那一算不就知道是从过去具体的哪个时间点开始的了，这和不确定的过去是矛盾的了？不是说好不确定的过去吗？

很遗憾，喵哥想告诉你

老外的脑回路就是这样的，你必须接受。

老子不想算就是不算，它就是不确定的。

别显摆你数学好，算减法不用计算器。

老外说，我关注的是这件事完成了，我要突出事完成了，什么时候发生次之。

老外说，我关注的是这件事什么时候完成的，我要突出事情发生的时间，事完成了次之。

重要的事情说三遍：

我们可以用时态来表现重要性（优先级）。

我们可以用时态来表现重要性（优先级）。

我们可以用时态来表现重要性（优先级）。

有做减法的时间不如打开雅思Easy姐App背几个单词呢