Responding to yes/no questions: Yes, I do. No, she isn't. Yes, they have.
Yes, + subject + auxiliary (do/does/did/am/is/are/have/has/can/will...)
No, + subject + auxiliary + n't
Short answers respond to questions
💡 Don't repeat the main verb in short answers. Use only the auxiliary.
✓'Do you like coffee?' 'Yes, I do.'
✗'Do you like coffee?' 'Yes, I like.'
Don't repeat the main verb.
✓'Is she coming?' 'No, she isn't.'
✗'Is she coming?' 'No, she doesn't.'
Match the auxiliary (is, not does).
✓'Have you been there?' 'Yes, I have.'
✗'Have you been there?' 'Yes, I do.'
Match 'have' with 'have'.