Do, Does and Did

Do and does are used when we want to ask yes/no questions.

We use do or does depending on the subject. Below are two sentences with two different subjects,she and you.

Ex:

1. Does she like coffee? yes, she does  -  No, she does not 
2. Do you play guitar?  Yes, I do - no, I do not
3. Do they come with us?  yes, they do! - No, they do not 

We can use contracted forms also in the negative form of the verb:

• I don't
• you don't
• He doesn't
• she doesn't
• It doesn't
• we don't
• they don't

how we can use it in past?: 

we just have to change do or does  (it depends of the subject) for DID

EX: 

Did she like coffee? ... Some day she likes coffee, but not now.