English — Short answers
In English you rarely answer a yes/no question with a full sentence. You reply with the subject plus the auxiliary from the question: Yes, I do / No, she isn't / Yes, they can.
How it works
Repeat the same auxiliary the question used (do/does, is/are, can, have), with the pronoun subject. Positive short answers keep the auxiliary full (Yes, I am); negative ones usually contract it (No, I'm not / No, they don't). Never add the main verb: say Yes, I do, not Yes, I do like.
Examples
| Question | Short answer |
|---|---|
| Do you like tea? | Yes, I do. / No, I don't. |
| Does she work here? | Yes, she does. / No, she doesn't. |
| Are you ready? | Yes, I am. / No, I'm not. |
| Is he your brother? | Yes, he is. / No, he isn't. |
| Can they swim? | Yes, they can. / No, they can't. |
| Have you finished? | Yes, I have. / No, I haven't. |
| Will it rain? | Yes, it will. / No, it won't. |
| Was the film good? | Yes, it was. / No, it wasn't. |
Good to know
A positive short answer is never contracted: say Yes, I am, not Yes, I'm. And beware of I am: its short answer is Yes, I am but its negative is No, I'm not (there is no "amn't"). Also, don't answer with the wrong auxiliary — reply to Do you…? with do, not with a form of be.