1) What is a yes-no question?
In English, a yes-no question ask if something is true or not.
Examples:
Are you tall?
Do you speak French?
2) How to form a yes-no question
- If a sentence contains 'to be', an auxiliary verb or a modal verb, we move it to the beginning of the sentence to form a yes-no question.
Examples:
(+) You are happy.
(?) Are you happy?
(+) The builders were working here all day.
(?) Were the builders working here all day?
(+) They can swim.
(?) Can they swim?
- In the present simple, there isn’t an auxiliary verb, so we use 'do' or 'does'.
Do + I / You / We / They + Verb
Does + He / She / It + Verb
Examples:
(+) You speak French.
(?) Do you speak French?
(+) She lives in Spain.
(?) Does she live in Spain?
- In the past simple, there isn’t an auxiliary verb, so we use 'did'.
Did + Subject + Verb
Examples:
(+) Ann watched TV.
(?) Did Ann watch TV?
3) How to answer a yes-no question
- If a question begin with 'to be', an auxiliary verb or a modal verb, we use it to answer this question.
Examples:
(?) Are you happy?
Yes, I am / No, I am not.
(?) Were the builders working here all day?
Yes, they were / No, they were not.
(?) Can they swim?
Yes, they can / No, they cannot.
- In a present simple question, we use 'do' or 'does' to answer it.
Examples:
(?) Do you speak French?
Yes, I do / No, I don’t.
(?) Does she live in Spain?
Yes, she does / No, she doesn’t.
- In a past simple question, we use 'did' to answer it.
Example:
(?) Did Ann watch TV?
Yes, she did / No, she didn’t.