"Are you sure sure" — is this repetition grammatically correct?

A typical conversation among members of my age demographic could go like this:

Person 1: Did you know that x > y?!?

Person 2: Are you sure?

Person 1: Yeah, I'm sure.

Person 2: Are you sure sure?

Is this grammatically correct?

Solution 1:

I don't think "grammatically correct" is really a meaningful issue in respect of this relatively common spoken usage - but if I have to have an opinion, I'd say it's valid but informal.

In general, to be a [noun] noun], or be [adjective] [adjective] is simply an informal way of adding emphasis.

Often it's because the word being repeated has acquired multiple shades of meaning - arguably in OP's example the word sure can mean anything from "Okay, I guess so" to "I would stake my life on it". The repetition is intended to focus attention on the primary meaning (certainty).

Solution 2:

Modern slang in North America (it doesn't seem to be restricted to a single age group) doubles a word to indicate emphasis, or in some cases that it's "really" whatever the word is - either that it truly literally is, that it is some sort of examplar of the word, or that it is a lot of whatever the word indicates.

• Joe and Sue are coming as a couple, but they're not a couple-couple.
• I told him I was flexible and now he thinks I'm flexible-flexible.
• I have to do some work but it's not work-work, I'm just booking some plane tickets

Language Log has quite a few mentions of this. Try http://languagelog.ldc.upenn.edu/nll/?p=3286 , http://itre.cis.upenn.edu/~myl/languagelog/archives/004591.html and http://itre.cis.upenn.edu/~myl/languagelog/archives/004594.html for starters - they have links to research papers, and/or comics. Can't lose, really.

Solution 3:

I agree with both FumbleFingers and Kate Gregory.

However, in this particular case, it seems to me that the sentence actually implies: "Are you sure [that you are] sure?". If the dropped words are correctly understood, the sentence makes perfect sense. It is not merely adding emphasis.

Grammar may not allow dropping words arbitrarily, though.

Solution 4:

It is correct in that it is understood and a recognizable part of speech. I would consider it slang but whether or not slang is correct, that's a question for endless debate. I do disagree with the idea that this emphasis is only used on nouns as one of the most common use cases I am aware of is for emphasizing a verb.

Yeah, I like Susie but I don't like like her.

I'm not sure of the correct way this is written, probably because it is rarely written. (like like, like-like, like like, etc...)