Мы употребляем do и don't для того, чтобы построить вопросительные и отрицательные предложения в простом настоящем времени:

• A: do you know Peter? B: Yes. We are old friends.  
• A: Do you like this music? B: Yes. It's great.  
• A: Do they live here? B: No. They live next door.
  
• A: What's that? B: I don't know.  
• A: Do they enjoy the theater? B: No. They don't go out very often.

Мы употребляем does и doesn't (does not) в вопросительных и отрицательных предложениях с местоимениями he/she или it:

• A: Is Helen at home? B: Helen? She doesn't live here.

Отрицательной формой глагола have часто являются сочетания don't have или doesn't have, но мы также можем сказать haven't или hasn'r.

• I haven't any money.
• She's got some, but he hasn't any.

Вопросительной формой глагола have часто являются сочетания Do you have... ? и Does he have... ? Но вы также можете сказать Have I... ? Have you... ?

• A: Have you any children? B: Yes. Two girls and a boy.
• A: Has he any brothers? B: No. But he has two sisters.

В Великобритании очень часто употребляется форма have got вместо have: I haven't got any money. She's got some, but he hasn't got any.
A: Have you got any children? A: Has he got any brothers?
B: Yes. Two girls and a boy. B: No. But he's got two sisters.