【学习笔记】懂你英语 核心课 Level 6 Unit 1 Part 2（II）听力 Talking about Verbs 2
When we talk about experience or results, we use the present perfect form.
This form uses "have" followed by the participle.
For regular verbs, this participle is identical to the past tense form.
For irregular verbs, this participle is often different.
When we use the perfect form, the primary focus is on the subject of the sentences, not the verb.
It emphasizes condition, experience or results rather than actions or events.
In these two examples, we see the contrast.
The top sentence gives the condition or state of the subject and the bottom sentence expresses an event.
The top sentence describes the condition of the subject of the sentence, she, rather than an event.
The fact that she has left the hotel is now a part of her experience, or state of being.
The bottom sentence expresses the action, or event: "she left," which is something she did.
In general, the past tense form expresses events or acts, and the perfect form expresses experience or conditions.【朗读】 一般来说，过去式表示事件或行为，而完成时表示经验或条件。
When we use the perfect form of the verb we focus on the state of the subject and not an action or event.
【选择】-Which sentence describes Bob's experience? -Bob has travelled to many countries.
【选择】-Which sentence expresses an event rather than a state or process? -He took a break.
【排序】(2) In fact, he was one of the worst students.
(4) However, he proved them wrong and did well enough to get into a top university.
(6) Now that he has graduated, he's ready to get a job.
(5) He enjoyed his studies and graduated a few months ago.
(1) In high school, John wasn't a very good students.
(3) When it came time to go to university, nobody expected him to pass the entrance examination.
Note that the past form expresses events at specific points or periods of time, such as last year or the past five years.
These events are distanced from the speaker's point of view.
The perfect form expresses the state of something from the speaker's point of view, not distanced in time.
These two sentences are incorrect and confusing, because they give two different points of view.
【选择】-Which sentence is strange? -He has finished his work last week.
Here are some sentences that use the perfect form.
He has finished practicing.
He has been practicing.
She may have eaten.
Her computer may have been stolen.
Some are simple, such as the first one, and some are complex, like the last one.
The last one is complex because it combines many verb forms, including the passive.
【选择】【跟读】-He has practiced hard... so he should do well in the competition.
【跟读】The weather has gotten worse.
【跟读】His computer was taken in for repair last week, so it should be ready soon.
【跟读】The fire might have been started by someone.
【跟读】The game has started already.
【跟读】His computer may have been taken by somebody.
【朗读】One of the biggest areas of confusion for students is the difference between the past tense and the present perfect.
【朗读】It's a counter-factual condition, which means it goes against what we know or believe.