
But that's really two utterances, phonologically and syntactically (the second is expanding on the first, so it's like I completely avoid alcohol. Just to forestall one distraction, let me note that a conversational turn may consist of of the one-word utterance "Yep" followed by another independent clause, of course: we find "Yep, except for the fish" in the WSJ corpus. Which means that there are zero occurrences of oh yep and oh nope (though there are 24 of "Oh, yes" or "Oh, yeah", and 15 of "Oh, no"). The Wall Street Journal corpus of 1987-89 newspaper prose, beloved of computational linguists because it offers 44 million words of easily searchable and freely available raw text for experimenting on, contains 4 cases of people quoted as saying "Yep" and 11 of "Nope" (note the capital letters there), but none at all of yep or nope. One small additional experiment confirms this. I suspect that they are bigger than can be accounted for by the observation that yep and nope are found only in direct reported speech while yes and no occur in purely written English.

These are really substantial differences - three orders of magnitude.

You can also find about 60 thousand Google hits on the web for oh nope but you can find about 24 million for oh no. But the point is that you can find about 24 million for oh yeah, and about 60 million for oh yes. It is true that you can find about 160 thousand Google hits on the web for oh yep. But even raw Google hit counts are pretty convincing evidence that Heinz is right on the level of unusualness. Naturally in a case of casual speech like this you get plenty of individual variation. I can't do anything about them but for you, who have continued reading into the third paragraph, let me make it very clear that of course I agree the constraint is not absolute. Now, a hundred commenters are going to waste their time and yours by pointing out below (without even reading as far as this) that they have heard Oh, yep, so I'm wrong. In particular, he noted (on receiving an email from a Chinese student who agreed to a meeting by writing "Oh, yep", and noticing that it seemed odd) that the -final pronunciations don't seem to occur when preceded by the interjection oh.

But my colleague Heinz Giegerich just pointed out to me a surprising constraint on the final- pronunciations: for a long time those pronunciations have been current only as single word utterances. No also gets a final unreleased sometimes, hence the spelling Nope (notice that in each case there is a conventional spelling of the -final pronunciation for use when direct reporting speech, e.g. Everybody acquainted with colloquial English knows that Yes has alternations in pronunciation: it may lose its final and add a centralizing offglide to become Yeah, and it may pick up an alternative final consonant, an unreleased (simulating the sudden closure of the lips at the end of the utterance), to make Yep.
