(1) The simple present tense indicates an action or state of being that occurs frequently or habitually at this stage, or describes the characteristics of the subject.

① Common adverbials of time in simple present tense sentences: often, naturally, sometimes, always, every day, etc. ), once/twice, a week, etc. ), on (Sunday, etc.). ), never, in (morning, etc.). For example, they go to the Palace Museum once a year/they often discuss business in the evening.

(2) When expressing objective truth, facts, people's skills or current situation, there is generally no adverbial of time in the sentence. The earth moves around the sun. /Light travels faster than sound.

(3) indicates what will happen (such as arranged things) or what will be done according to the schedule. The future can be expressed in the simple present tense, and the future time can be included in the sentence. The train for Haikou leaves at 8 a.m.

(4) in adverbial clauses of time (guided by when, after, before, while, never, only as, etc. ) and conditional adverbial clauses (guided by if, never), if the simple present tense is used instead of the simple future tense, the sentence can have a future time. Please call me as soon as you arrive in Germany. If it rains tomorrow, we will have to stay at home.

⑤ The simple present tense can be used in inverted sentences to indicate the action that is taking place, and the verbs are mainly coming and going. Here comes the bus. /The bell is ringing.

⑥ The simple present tense is often used to explain sports competitions or fables. Now the midfielder has the ball and he controls it.

⑦ People's psychological activities and sensory actions are generally expressed in the simple present tense, not in the present continuous tense. Common verbs are: like, like, hate, dislike, want, hope, think, understand, remember, forget, meaning, need, hear, feel, I think it's going to snow. /I really hope you enjoy your stay here.

(2) The simple past tense indicates an action or state that occurred at a certain time in the past, which may be one-off or recurrent.

Happen.

(1) indicates a one-off action at a specific moment in the past. The adverbial clauses of time are: at (8) (yesterday morning), (10 minutes ago, When. I got up at six this morning. Little Tom broke the window at 9: 30 this morning. When he entered the room, he saw a stranger talking to his father.

(2) When expressing a one-off action in the past period of time, adverbials of time include: yesterday, last year (year), etc. ), in (1998, etc. He came to our city in 2000. He came to our city in 2000.

(3) Adverbials of time include: finally …, at …, from … to …, for (10 year), often, generally, sometimes, always, never, etc. When Mr. Jackson was young, he generally went to evening classes. He goes to the rich man and borrows books from him every day.

(4) Stories, memories of past experiences, past events known by both parties, etc. Generally used in the past tense, adverbial of time is often omitted. I happened to meet Ross in the street.

(3) The general future tense indicates an action or state that will happen at a certain time or often in the future.

The adverbials of time in the general future tense are: tomorrow, today (afternoon), next year (year), one day, now, soon,

A certain day, a certain time, the future, when to lead clauses, etc.

(2) The future tense formed by will indicates that the action has nothing to do with people's subjective wishes. "shall" is used in the first person "will"

For everyone. I will graduate from this school soon/please stay alone after I leave.

(3) "am/is/are to+ verb prototype" means what you intend to do or prepare to do, or what will happen subjectively, while "am/is/are to+verb prototype" means the action in the arrangement or plan. A man told them that this woman would give birth to this special child. It's going to rain soon.

It means that a person decides to do something temporarily and can be expressed by will. I'll go to the lab and get some.

Chemicals. So please wait for me. I'm going to the chemistry lab to get some medicine. Please wait for me. )

⑤ The present continuous tense and the general present tense can also indicate the future. (See corresponding tense)

⑥ shall and will are equivalent to modal verbs in some oral interrogative sentences. Shall is usually used in the first person and will is used in the second person. Shall we go to the zoo next Saturday? Shall we go to the zoo next Saturday? Would you please open the door for me? Can you open the door for me? )

⑦ "Be to+verb prototype" means what will happen according to the plan. An angel camel told her that she would have a special boy.

(4) The present continuous tense means an action that is being carried out now or an action that occurs at this stage but not necessarily at this moment.

① The present continuous tense consists of "auxiliary verb be(am is are)+ present participle".

The adverbials of time in the present continuous tense are: now, this …, these …, and so on. , but they are often not used. What are you doing in the tree? What are you doing in the tree? I am writing a novel these days. (writing a novel recently)

(3) indicates the upcoming action, generally referring to the recently arranged things. Common verbs are: come, go, stay, leave, spend, do, etc. I'm coming now. /What are you going to do tomorrow? What will you do tomorrow? He will leave soon.

(4) To express frequent or repeated actions, it is often used with frequency adverbs such as always to express feelings such as praise, dissatisfaction or disgust. He always borrows money from me and forgets all about it after a while.

(5) The past continuous tense indicates an ongoing action at a certain moment or stage in the past.

① The past continuous tense consists of "was (singular in the first and third person) or were (singular in the second person, plural in everyone)+present participle".

The adverbials of time in the past continuous tense are: then, at that time, at this time yesterday, at 8 o'clock yesterday (morning), (a year ago), the adverbial clauses of time introduced by when. He was cooking at this time yesterday/when I saw the little girl, she was playing with her toys.

(3) Used in an object clause or an adverbial clause of time, indicating that it is carried out at the same time as the main clause and lasts for a long time. There is usually no adverbial of time in sentences. It happened when she walked by/they sang a lot of songs while walking in the dark forest.

(4) It can also indicate actions that occurred frequently or repeatedly in the past stage. It is often used with frequency adverb always to express praise, dissatisfaction or disgust. He always borrowed money from me when he lived here.

(6) The present perfect tense indicates an action that happened in the past and still has an impact on the present, or an action that started in the past and continues to the present, and may even continue.

① When it is completed, it consists of "auxiliary verb have (has)+ verb past participle".

(2) Adverbials of time include: ready, not yet, just now, once, twice, once, never, three times, before, etc. I have never seen such a good photo before. /He has just gone to England. He has just gone to England.

(3) The adverbial clauses of time are: for (two years), since 1990, since (two weeks ago) and since. I have been away from my hometown for thirty years/Uncle Wang has been working there since the factory opened.

(4) In spoken language, have got often means having. There are books in their library.

⑤ The difference between being there and being there: Being there means people are not there, and being there means people are there. Where is Mr. Li? -He went to England. Where is Mr. Li? He went to England. )/-Do you know anything about Beijing? Yes, I have been to Beijing three times. Do you know anything about Beijing? Yes, I have been there three times. )

⑥ In the perfect form, the instantaneous verb (one-off action) cannot be used with adverbial indicating a period of time. At this time, the instantaneous verb must be changed into a progressive verb or a state verb. See the following table for specific changes:

The perfect tense of instantaneous verbs → the perfect tense of progressive verbs or state verbs.

I have been there ... I have been in ... (for two years).

Has come to ... has been here (1990)

Leave (have) away from ...

Arrive at ... have been at ...

Already dead

start

it's over

Bought ... had ...

Borrowed ... kept ...

Join ... has been ...

Or use the following sentence pattern:

Yes/has+(how long)+since+subject (person)+predicate (past tense)+...+past time adverbial

[Note] Other tenses have similar problems. Remember, the point is that instantaneous verbs cannot be used with adverbials indicating a period of time. How long can I keep this book? How long can I keep this book? Keep replaces the word "borrow" in the sentence.

(7) Past perfect tense The past perfect tense indicates actions that have been completed in the past or before the action occurs. In short, the time expressed in the past perfect tense is "the past past".

① The past perfect tense consists of "auxiliary verb had+ verb past participle".

(2) Adverbials in the past perfect tense include adverbial clauses led by (yesterday), by then, by (last ……) or when and before. Sometimes words like "always", "only", "once", "once", "never" and "never" appear in sentences, and there are adverbials of time composed of "because …" or "since …". When the teacher came, they had already cleaned the classroom; She had left before he realized that the woman was a liar.

The past perfect tense is often used in object clauses, post-leading clauses, or clauses are pre-leading main clauses. After putting on my shoes and hat, I walked into the darkness. I put on my shoes and hat and walked into the darkness. He said that he had never seen a kangaroo before. He said that he had never seen a kangaroo before. )

(8) Past Future Tense The past future tense indicates the action or the state of existence expected to happen in the past.

① The past and future tense consists of "auxiliary verb should (first person) or would (second and third person)+verb prototype". In American English, past tense and future tense auxiliary verbs are "would+ verb prototype".

② In the past tense and the future tense, the adverbials of time in the object clauses are: later, soon, next (day).

③ The simple past tense should be used instead of the past tense and the future tense in the time adverbial clause and the conditional adverbial clause. For example, he promised that he would pay me a lot of money if I helped him finish the project. Whenever he is free, he will sit down and read some books.

④ Will or would is used to express pure future tense, and was/were going(+ verb prototype) is used to express intention or subjective thoughts. She told me that she will be 18 next month. She told me that she would18 next month./She told me that she would take her pet dog for a walk.

The past future tense can also indicate an action that often happened in the past. When it rains during the day, he will take an umbrella.

(9) The present perfect continuous tense means that an action has continued from the past to the present and may continue. It has the dual characteristics of present perfect tense and present continuous tense, and the structure is the present participle of "verb have/has+bee+". I have been swimming in cold water for about two hours. /How long have you been waiting here? How long have you been waiting here? )