Auxiliary verbs

Do

Present Simple (I, you, we, you, they)

Do you work?

Yes, I do. No, I don’t.

Does

Present Simple (He, she, it)

Does she like to study English?

Yes, she does. No, she doesn’t.

Did

Past Simple

Did you watch TV yesterday?

Yes, I did. No, I didn’t.

Will

Future Simple

Will he go to Washington, D.C?

Yes, he will. No, he won’t.

Would

 Future (Conditional)

Would you help me to organize the party?

Yes, I would. No, I wouldn’t.

Notice: Do not = don’t / does not = doesn’t / did not = didn’t / will not = won’t / would not = wouldn’t