1. The general present tense, the general past tense, the general future tense, the present continuous tense, the past continuous tense and the present perfect tense Positive and negative sentences change There be, there be, there be, there be, there be, there be 2. Direct speech changes to speech knowledge, including his declarative sentence General questions, special questions, affirmative and negative imperative sentences, including 4 examples of his tense change! 3. Summarize the usage of if, including conditional adverbial clause, two examples in each case! Key points: modal verbs, general present tense, past tense, examples!

1. The general present tense, the general past tense, the general future tense, the present continuous tense, the past continuous tense and the present perfect tense Positive and negative sentences change There be, there be, there be, there be, there be, there be 2. Direct speech changes to speech knowledge, including his declarative sentence General questions, special questions, affirmative and negative imperative sentences, including 4 examples of his tense change! 3. Summarize the usage of if, including conditional adverbial clause, two examples in each case! Key points: modal verbs, general present tense, past tense, examples!

*^*General present tense
1 'means the objective existence without time limit
Example: the earth rotates on its axis
The earth rotates on its axis
2 'is used to action now
He always sleeps with his windows open
He always sleeps with the window open
3 'means present state and present instant action
Someone's at door, Carol
Someone's outside, Carol
4 'is the future time
I hope you have a good time
I hope you have a good time
5 'means the expiration time
Example: I hear poor old Mrs Smith has lost her son
I heard that poor old Mrs. Smith had lost her son
---------------------------------------------------------------
*…… *General past tense
1 'is the past time
We visited a factory last Friday
We visited the factory last Friday
2 'means present time and future time
If I had the money now, I'd buy a car
If I have money, I want to buy a car
---------------------------------------------------------------
*^*Now progressive
"1" is an action in progress
He is living in Shanghai
He lives in Shanghai now
2 'means the action that has been going on at this stage
She complains about the house
She complained about the house
3 'means to arrange the actions that will happen in the near future according to the plan
I'll think about it while you're writing the report
I'll think about your report
4 'means the action and tone of the past
I'm wondering if I may have a world with you
I think if I have the feeling of a world with you
---------------------------------------------------------------
*…… *Past progressive
"1" refers to the action in progress at some time in the past
They were building a dam last winter
They were building a dam last winter
2 'means a habitual action in the past
Example: Alice was constantly changing her clothes
Alice kept changing her clothes
3 'is an action in the past and in the future
He told me to wake him up if he was sleeping
He told me to wake him up if he was sleeping
"4" means action in present time and future time
It's time we were leading
It's time for us to go
Hope to adopt·····