VOA日常语法|一般过去时和现在完成时
下载音频：MP3 作者：Adam Brock 来源：美国之音慢速英语
In this week’s episode of Everyday Grammar we’re going to help you understand the difference between the simple past and the present perfect. English learners often confuse these two verb tenses.
Let’s start with an example. Can you tell the difference between these two sentences?
Sentence one: I saw the movie.
Sentence two: I have seen the movie.
Sentence one uses the simple past tense. Sentence two uses the present perfect tense.
“I saw the movie” and “I have seen the movie” both refer to an action that was finished in the past. But there is one important difference: “I saw the movie” suggests that you saw the movie at a specific time in the past. “I have seen the movie” suggests that you saw the movie at an unknown time in the past.
Use the simple past to talk about a finished action that happened at a specific time. For example, “I went out with my friends last night.” The adverb “last night” is not required, but it does help clarify that the event happened at a specific time.
That’s the easy part. Now let’s talk about the present perfect. You form the present perfect by using “have” or “has” followed by the past participle form of the verb. For example, “I have graduated from college.” The present perfect confuses English learners because it refers to a past action. It is also called “present perfect” because speakers use it to stress the importance of a past event in the present. The sentence “I have graduated from college,” emphasizes the present effect of a past event -- graduation. The exact time of the graduation is not important.
There are four more common situations that require the present perfect.
First, it can express a repeated action. When an action happened more than one time in the past, use the present perfect. For example, “I have seen the movie three times”.
Second, it is common to use the present perfect with the words “for” and “since.” “For” and “since” are adverbs that tell about the duration of an activity. They answer the question “how long?” For example, “I have studied English for a long time”.
Third, the negative adverb “never” requires the present perfect. You can say, “I have never been to France.” You would not say, “I did never go to France.”
Finally, when asking a question in the present perfect, use “ever,” as in, “Have you ever won the lottery?” Listen for the present perfect question in this song by the American rock band Creedence Clearwater Revival.
I wanna know have you ever seen the rain?
I wanna know have you ever seen the rain
Coming down on a sunny day?
In an informal situation, you can take out the word “have” in a present perfect question. Listen to actor Jack Nicholson playing the Joker in the 1989 movie Batman. Before the Joker takes his victims, he asks them an unusual question.
Tell me something, my friend. You ever danced with the devil in the pale moonlight?
Here’s a tip: pay close attention to adverbs. Adverbs give hints, or clues, about which verb tense you should use. Take a look at the reference list below.
A good way to practice the present perfect is to ask an English-speaking friend if he or she has ever done something. “Have you ever flown in an airplane?” or “Have you ever seen the Grand Canyon?” You could even ask something more profound like, “Have you ever seen the rain coming down on a sunny day?”
I wanna know have you ever seen the rain
Coming down on a sunny day?
I’m Ashley Thompson.
And I’m Jonathan Evans.
Adam Brock wrote and produced this story for VOA Learning English. Jill Robbins was the editor.
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Reference
Forming the present perfect
Have/has + past participle verb
Ex. I have proven her theory.
Ex. She has gotten promoted.
Common adverbs in the simple past: last night, last year, yesterday, today, ago, first, then, later, when
Ex. Yesterday morning, I went to the store.
Ex. When I lived in Boston, I worked at a deli.
Common adverbs in the present perfect: before, after, already, yet, for, since, recently, still, time
Ex. I have already eaten.
Ex. I have already visited Angola three times.
Tip 1: Be careful of irregular verbs in the present perfect. With irregular verbs, the simple past and the past participle form are usually different.
INCORRECT: I have already did it.
CORRECT: I have already done it.
Tip 2: Make sure to use “has” for the third person in the present perfect.
INCORRECT: She have not read the book yet.
CORRECT: She has not read the book yet.
Click here for a list of common irregular verbs.
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Words in This Story
simple past tense – n. the basic form of the past tense in English. It is used to describe events that finished at a specific time in the past.
present perfect tense – n. A grammatical combination of the present tense and the perfect aspect, used to express a past event that has present consequences.
unspecified – adj. not specified or particular
clarify – v. to make (something) clear or clearer: such as
duration –n. the length of time that something exists or lasts
victim – n. a person who has been attacked, injured, robbed, or killed by someone else
pale – adj. light in color
profound – adj. having or showing great knowledge or understanding