1. Usage of not 1. Not is an adverb, often located after be verb, modal verb and auxiliary verb, and it means "not". For example: Tom is not a young man. Tom is not a young man. not can be placed before gerund, present participle and infinitive symbol to to form its negative form. For example: He asked me not to be late. He asked me not to be late. Not finishing her homework, Jenny had to stay at home. Not finishing her homework, Jenny had to stay at home.

2. Not can be placed after the verbs see, appear, hope, believe, suppose, think and the adverbs perhaps, probably and be afraid, expressing negative meaning. For example: —Will they come back from London next week? —I hope not. The full form should be: I hope they will not come back next week.

3. Not can be used with words such as every, both, all, etc., meaning "not, not all", indicating partial negation . For example: Not both of them are students. Not both of them are students. Its complete negative form is: Neither of them is a student. Neither of them is a student. Not all the students have seen this film. Not all the students have seen this film. Its complete negative form is: None have seen this film. No one has seen this film.

4. Not can also be used in elliptical structures to replace the negative form of the previously mentioned words, phrases and sentences. For example: Hurry up. If not, you'll be late. Hurry up, otherwise, you'll be late.

2. Usage of no 1. No is used as an adverb (1) to introduce negative answers. For example: —Do you like a cat? —No, I don't. No, I don't like it. (2) no is used to refuse the other party's suggestions or help. For example: —Will you please have some tea? —No, thanks. (3) no is used to express disagreement with the other party’s request. For example: —Can you lend Wei Hua ten yuan? —No, I can't. Oh, no. (4) no is used before the comparative form of adjectives and adverbs, and it means "not at all". For example: They are no older. They are not old at all.

2. When no is used as a noun, it means "no, rejection" or "opponent". For example: The noes are crowding there. The opponents are crowding there.

3. no is used as an adjective. (1) When no is placed in front of a singular countable noun, it is equivalent to not a; when it is placed in front of a plural countable noun or an uncountable noun, it is equivalent to not any, meaning "nothing, nothing", "far away" No, not at all.” For example: No teacher and no student has come yet. No teacher and no student has come yet. Kate is no teacher.(=Kate is not a teacher.) Kate is not a teacher at all. (2) no is used in orders or signs to mean "forbidden". For example: No smoking. No smoking. (3) no is used in the structure "there is no doing", meaning "impossible". For example: There is no expecting what will happen. There is no expectation of what will happen.

4. No can form a compound pronoun with words such as body and thing. For example: Nobody will go to see the film tomorrow.