Tense is a verb form that expresses behavior, action and state under various time conditions. So when we say tense structure, we mean the verb form corresponding to tense.

English tenses are divided into 16: simple present tense, simple past tense, simple future tense, past future tense, and their continuous tense, perfect tense and perfect continuous tense. This paper focuses on the usage and precautions of the most common tense 1 1.

1. General present tense: I started to learn this in primary school. Everybody knows that. Emphasize a few points and leave.

A) indicates the actions, situations, states and features that are happening now. I'd like a cup of tea, if it's not too much trouble.

B) Idiom: I should have accumulated this by myself at ordinary times, because there are too many idioms, so I don't need to explain them.

Believe it or not, his discovery caused a sensation in the scientific community.

It is often said in spoken English that believe it or not means "believe it or not" and "what I said is true". Believe it or not is a fixed expression, which is equivalent to parenthesis. I believe that the phrase has no morphological changes. Pay attention to this. I will teach you the usage of gerund in the future, and the subject will be involved.

C) Regular habitual movements.

He always helps others. He always helps others. )

D) objective facts and universal truth. Especially if the context is not the general present tense, it is impossible to keep the tense of the main clause and the clause consistent. He said that the sun rises in the east. Pay attention to this sentence, such problems will often appear in attributive clauses in the future, and the details will be discussed at an appropriate time, but you must first have a concept that objective facts use the simple present tense regardless of the tense of the predicate.

E) indicates the action that will happen according to the regulations, plans or arrangements (limited to some verbs that mean "come, go, move, stop, start, end and continue"). ) can be used with adverbials indicating future time. Common usage is: planes, trains, ships, cars and other means of transportation that run at fixed points on a regular basis.

When does this plan leave? Pay attention to this sentence, that's how it is used. Some people will notice this problem: the plane takes off at 3 o'clock this afternoon. Why not use the future tense? Yes, it's strange, but that's how it's used.

F) In the adverbial clauses of time and conditions, the simple present tense (sometimes the present perfect tense) is often used to indicate future events.

By the time you finished the report, I had been waiting for three hours.

2. Usage in the present: It is easier to teach this from the first day of junior high school than the general present. It means the action you are doing now, but pay attention to some verbs that cannot be used in the progressive tense. These words are called instantaneous verbs, such as open, borrow, etc. I often encounter it when I finish, so I should pay attention to accumulation at ordinary times.

3. done: important test sites, almost all of them are perfect tenses after the second year of high school.

A) indicates that the action has been completed or just completed.

I just finished my homework.

B) indicates the action or situation that started from a certain time in the past, continued to the present, and may continue. Progressive verbs are often used at this time. Adverbials of time are often used to indicate a certain point in the past, or a period of time, or the present time. It's the same when you make contact here. You can't use instant verbs, ★★★☆☆☆☆☆.

C) indicates an action or situation that happened in the past but still has an impact on the present. Some verbs are usually used, such as: arrive, start, find, give, lose, etc.

John broke his left leg. John broke his left leg. )

note:

A) The present perfect tense is a link between the past and the present. The difference between the present perfect tense and the past tense is that the present perfect tense emphasizes the dynamic nature of the action, or is influenced by the dynamic nature, which is the dynamic result and has an impact on the present; The past tense only indicates actions that happened at a specific time in the past, and has nothing to do with the present.

He worked in that hospital for eight years. He used to work in that hospital for eight years. This is just telling a past fact. He is not in the hospital now. )

He worked in that hospital for eight years. He worked in that hospital for eight years. He used to work and still works in that hospital. )

B) Because the completion of the adverbial of time containing for plus a period of time or since plus a time point is dynamic and continuous, terminal verbs or instantaneous verbs cannot be used.

My sister has been married for five years.

My sister is married. Don't disturb her. (terminal verb)

C) The sentence pattern "This is the first/second/third" tense that needs to be completed ... Time is up ... ".

This is the second time that our company's products have been exhibited in the international exhibition. )

D) the two tenses used in the sentence pattern "it is/hasbeen" ... since "both" are correct.

It's been 10 years since I last saw him. )

E) In sentence patterns such as "not earlier than", "almost/hardly when", "before" and "before", when the main sentence needs to be completed.

Up to today, I haven't seen the professor. )

4. I have been doing it: it is very similar to the present continuous tense.

1) Usage: indicates that an action started at a certain time in the past, continues or appears repeatedly today, or will continue into the future.

We have been working on this project for over a month. Up to now, we have been working on that project for more than a month. )

2) Note: Compared with the present perfect tense, the present perfect tense emphasizes that the action or state has been continuous or repeated from the past to the present.

5. Simple past tense

A) indicates an action or situation that happened at some time in the past.

I went to Beijing last year.

B) Show past habitual actions. Especially the sentence pattern expressed by would/ used to do itself represents the past tense.

I used to live here. Pay attention to the difference between being accustomed to and being accustomed to. Habit refers to being accustomed to. The former is an infinitive symbol, the latter is a preposition, followed by a noun, gerund and pronoun. )

C) Sometimes it can replace the simple present tense to express a smooth, polite, polite and negotiating tone.

Do you mind if I sit here? Can I sit here?)

Can you pass me the pen?

note:

A) Pay attention to the collocation of adverbials of time. The adverbial of time in the past tense should be a word or phrase indicating a certain time in the past, such as yesterday, last month, in 1999, two days ago, etc. It should not be used with recent, past 10 year, this month, etc. Because such adverbials of time are related to the present, we should use the present perfect tense or the simple present tense. Note that the second day will be the test center, and you can't escape. You will take the exam almost every time.

B) The negative forms and interrogative forms are special: you can write them correctly. Take the negative form as an example: it can be used without doing it, without doing it, or without doing it.

6. Past perfect tense

Usage: indicates the action that has occurred or the state that has existed before a certain time or action in the past. It is what we often say: expressing past behavior or state.

Draw a timeline to complete the past _ _ ● _ General past _ ◇ _ General present _ _ _ _ _ _

2) Note: The logical relationship of "past past" is often reflected by context, not necessarily limited by a certain adverbial of time.

Someone was in our room just now, because when we opened the front door, I noticed a burning cigarette butt on the floor.

7. The past future tense (would/ should do) means something that will happen from a certain time in the past. In fact, it is no different from the future tense.

I said on Thursday that I should meet my friends the next day.

8. Past continuous tense (being done)

A) Represents an action that occurred at a specific time in the past.

I was doing my homework this time yesterday.

B) If one of the main sentences guided by adverbials of time such as when and while is the simple past tense, the other sentence is often used in the past continuous tense.

I was washing my hair when you knocked at the front door.

9. Simple future tense

A) the basic structure is will/shall do. Old English thinks that will is used in the second and third person, and shall is used in the first person. Later, it is not rigid, and will is more commonly used. I will get home at 10.

B) Some verbs, such as: arrive, approach, come, do, finish, go, have, leave, open, play, return, sleep, start, stay, etc. Used in the simple continuous tense, usually used with adverbial of time indicating future time, indicating future tense. Be going is the most common contact in grade one, and will/shall appeared later. Others such as little sleep. I have hardly seen the sleep used in junior high school. It is also common to ask for leave, come and arrive.

My mother will come to see me next week, and she will stay here until May.

C) about to do can be used when it means "soon, soon". Emphasize what to do in the near future or soon, often used with when. I was about to speak when you interrupted me.

D) five usages of d)be to do:

A) means "something will happen or do something as planned."

I will see her in the laboratory on Monday. You are sure to see her in the lab on Monday. )

B) What to do or not to do (the tone is close to that of should, must, should and have to) indicates the imperative and persuasive tone.

Children, you should go to bed and keep quiet. Our guests will arrive in five minutes. Children, you must go to bed and be quiet. Our guests will arrive in five minutes. )

C) What is possible or impossible (close to possible, possible)

Example: How can I repay this debt? How can I afford such a big debt? )

D) It will happen, and it will happen in the future.

I assure you that this matter will be settled as soon as possible. Be patient.

A. Will be taken care of

C. being cared for

The key point of will attended to is that when it means "deal with and solve", attend is an intransitive verb and must be used with to. In addition, from the context, things are obviously not solved, so we should use the passive voice of the future tense. The answer is B.

A) yes, b) yes, c) yes, d) yes.

The answer is a) yes. If we want to avoid food shortage, we must work harder to increase agricultural production.

E) The sentence pattern that can also mean "about to do something" is about to do something. The coach almost gave up the game because our team had scored 7 points.

note:

Adverbial clauses guided by conjunctions such as if, when, as, only, after, before, in case, till, till, and adverbs with conjunctions (immediately, the moment, directly) generally use the present tense instead of the future tense. The perfect tense can be used when continuity or dynamics are emphasized.

I hope his health will have improved when you come back next year. I hope his health will be much better when you come back next year. )

10.will be doing refers to the behavior or things that are happening at a specific time in the future.

Don't worry, you won't miss her. At that time, she will wear a red T-shirt and a white skirt.

1 1.will have done refers to an action or state that starts from a future time and continues to another future time, or an action or state that occurs at a future time but has an impact on another future time. It's like translating the present perfect tense into the future time period of the timeline. Its usage has changed from being related to the past and present to being related to the future and the future.

It is reported that the population of China will increase by 2 billion by the end of this century.