not
Use the word “not” to make verbs and adjectives negative.
- He does not have a book.
- This is not easy.
- That’s not a problem.
no or not
a. Use "not" with helping verbs.
Add “not” to a helping verb to make the main verb negative:
I have a book / I don’t have a book.
- They don’t have any problems. (don’t = do not)
- You haven’t had any coffee. (haven’t = have not)
- I will not go in there. (will not go)
- It might not work.
- This shouldn’t take long.
- We don’t like brussels sprouts.

- She isn’t going to work today. (isn’t = is not)
- She doesn’t have anything to do all day. (doesn’t = does not)
b. Use "not" with (be) + adjective.
It’s very common in English to us the main verb “be” and “not” before an adjective.
This is good. / This is not good.
(be + not + adjective)
- The test was not easy.
- The movie we saw last night was not interesting.
- They shouldn’t be so mean.
- It will not be difficult.
- She’s not happy.

- He is not happy.

- His job is not easy.
c. Use "not" before possessive pronouns.
The word “not” usually doesn’t go before a noun, but you can use it before a possessive pronoun: mine, yours, his, hers, its, ours, theirs.
- That’s not mine.
- It’s not yours.
- Those are not his.
- These are not hers.
- This car is not ours.
- The house is not theirs.

- A: Whose car is that?
- B: I don’t know. It’s not mine. (It’s not my car.)

- A: Are those his headphones?
- B: No, they’re not his. He borrowed them from a coworker.