Ch 15
Short Answers
Yes I do · No she isn't · So do I
Short answers use an auxiliary verb to answer yes/no questions — never "yes/no" alone, and never the full verb repeated.
Question
Do you like coffee?
Short answer
Yes, I do. / No, I don't.
NOT this
✗ Yes, I like. / ✗ Yes. (in formal contexts)
Do you...?
Yes, I do. / No, I don't.
Does she...?
Yes, she does. / No, she doesn't.
Did you...?
Yes, I did. / No, I didn't.
Are you...?
Yes, I am. / No, I'm not. (no contraction yes)
Is she...?
Yes, she is. / No, she isn't.
Were you...?
Yes, I was. / No, I wasn't.
Have you...?
Yes, I have. / No, I haven't.
Has she...?
Yes, she has. / No, she hasn't.
Can you...?
Yes, I can. / No, I can't.
Will you...?
Yes, I will. / No, I won't.
Should I...?
Yes, you should. / No, you shouldn't.
Yes, I am — no contraction in positive short answers with "be": "Yes, I'm" is wrong.
Agree positive
A: I like coffee. B: So do I. / Me too.
Agree negative
A: I don't like it. B: Neither do I. / Me neither.
Disagree positive
A: I love this film. B: I don't.
Disagree negative
A: I can't swim. B: I can.
Yes, I'm. (to "Are you a student?")
→
Yes, I am.
no contraction in positive short answers with am/is/are
Do you like coffee? Yes, I like.
→
Yes, I do.
short answer — use auxiliary, not full verb
Is she coming? Yes, she is coming.
→
Yes, she is.
short — don't repeat the main verb
A: I love pizza. B: So I do.
→
B: So do I.
inversion: so + auxiliary + subject
Recap
Rule
yes/no + subject + auxiliary
Yes, I do. / No, she isn't.
am/is/are: no contraction
Yes, I am. (NOT Yes, I'm)
positive short answer rule
Agreement
So do I (pos) / Neither do I (neg)
A: I like it. B: So do I.