I'm curious about knowing the reason why we say "I do" after "Yes" while answering a "do question".

Let's look at the following example:

Question: Do you speak English?

Answer 1: Yes
Answer 2: Yes, I do
Answer 3: Yes, I speak

The answer 1 is clear, nothing to ask about it. It's the same for answer 3.
But in the answer 2, why do we add "I do". What is the reason for doing so? What's the meaning of "I do". I wonder if "Yes, I do" expresses "Yes, I speak".

Could you please clarify that for me?


Do can stand for a whole verb phrase: it is sometimes called a "pro-verb" (different from a "proverb"!) on the analogy of a "pronoun"

Note that your Yes, I speak is not grammatical: speak in the sense of "talk in a particular language" requires an object. You could say yes, I speak it (though that doesn't sound very natural to me). If we wanted to repeat speak, we would say Yes, I speak English.

But much more natural is to use the pro-verb do, which can stand for a whole predicate (verb and objects or complements).

So in summary, we can say:


Yes, I speak English.

? Yes, I speak it. (there are probably contexts where this does occur, but not normally).

Yes, I do.

Note that we can't give the pro-verb do an object, unless for contrast or emphasis:

? Yes, I do English. This sounds odd, except in contexts like the following:

Do you speak German?

No, but I do English.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .