The only correct answer for that question is "Yes, I do". Do you have a pen? Yes, I do. "Yes, I have" works with a slightly different structure, which has the same meaning: Have you got have a pen? Yes, I have. It's a simple rule: use the auxiliary verb.

Gigi: The problem with what you were taught is that many foreign teachers of English, understand our language to be one of rigid rules, which must be absolutely followed. That may be true regarding some specific grammatical constructions, but it is not always true. English is very flexible. As a Native Speaker, I can communicate in several ways, as follows: (1) Yes, I have a pen. (2) Yes I do. (3) I do have a pen. (4) I have got a pen. (5) Here is my pen. (6) (I can simply hold my pen up for others to see, and wave it around.) (7) I can offer a casual response, without even using a complete sentence. One example is to simply answer back; "Yo!" My point is that in English, I can do just about anything I want to do. So can you. You can say "Uh-Huh" to be affirmative to the Pencil Question or the Garbage question. You can say simply, in answer to the question about taking out the garbage; "I did." You can say, "I have." or "I have taken the garbage out." You can say; "I did take the garbage out." or "It has been done." or, "I have done it." English is very flexible.

Both are right

Hey guys, I remember having been taught and having read in English grammar books that when we ask a question starting with "do" do you have a pen? the answer mustn't be "yes I have",but yes I do because the question starts with "do" not "have" That said from the other auxiliary perspective,there is no other alternative answer: Q-"Have you taken the garbage out as I told you to?" A-"Yes,I have",or "no I haven't" But if we construct the question differently with the helper " Do", "Do you think you can finish the report? "Yes,I do That's my opinion Have a nice day!

Hey guys, I remember having been taught and having read in English grammar books that when we ask a question starting with "do" do you have a pen? the answer mustn't be "yes I have",but yes I do because the question starts with "do" not "have" That said from the other auxiliary perspective,there is no other alternative answer: Q-"Have you taken the garbage out as I told you to?" A-"Yes,I have",or "no I haven't" But if we construct the question differently with the helper " Do", "Do you think you can finish the report? "Yes,I do That's my opinion Have a nice day!