Correct usage of the verb “do”

Question

Is it correct to use the word "do" twice in a row? For instance; "I do do that" or would you say "I do that"? "You do do that" or "You do that"?

Which is correct, or are they both correct?

Answer 1

In general "I do that" is enough. But if you want to emphasize that you "do" that you can use do twice. In question the first "do" should be on the first place. Do you do that? That is the only right variant.

Answer 2

It is the first use of the word 'do' that is incorrect in the sentence "you do do that". The correct response could be that "I have seen you do that" or "I have noticed that you do that"

Answer 3

Using "do" twice in a sentence, even in apposition, is not grammatically incorrect.

If you can say

Do you ever do anything you would be ashamed of?

which you certainly can, then you can also say

Oh, so you do do things you would be ashamed of?

or

I don't do anything I am ashamed of, but sometimes I do do things I find embarrassing.

Note that in my first example, a single do won't suffice. It would be awkward or at least archaic to say

Do you anything you would be ashamed of?

No modern-day speakers would ever say such a thing.

The construction even appears in the song "You Do Something To Me" by Cole Porter:

Do do that voodoo
that you do so well.

And, for a laugh, let's close with Sting's use of multiple *do*s:

De do do do, de da da da
that's all I want to say to you.

Obviously that's not the same grammatical use case, but it does have a logic all its own.