OK and all right

Is "OK" in use in British English? And if yes, what is the difference from "all right"

It's used in many languages all over the world, all dialects of English among them. I don't think there is any difference between "OK" and "all right".

By the way, I would say "if so" rather than "if yes".

- Kef

BTW, is it true that OK comes from Ol Korekt (or something similar)?

Yes, probably. http://en.wikipedia.org/wiki/Okay#Etymology:_.22Oll_Korrect.22_and_.22Old_Kinderhook.22

Is it possible that such usage is an example of how language changes, or is it just plain wrong? OK, all right, I like the "yes" and I think one could make a case for it in a colloquial sort of way. I think "if so" makes me pause or think just very briefly about what it references, but with the "yes" I got it right away and kept going. It's hard to say, really, because the "so" wasn't there originally.

Are you a native speaker, Grammar Crab? I've never heard one say "if yes".

"If yes" is used in questionnaries. Something like "Did you ever steal anything? If yes, enumerate the items, their value and amounts of taxes paid..." and other blah blah blah

True, you can say "if yes" in that case, but I think that construction is almost never used outside that very specific context. I think it occurs mainly because there is often a "Yes/No" box after the first question, before the "if yes" part. It's understood that "if yes" is short for "if you answered 'yes'".

- Kef

Yes, I am a native English speaker. I'd never -say- "if yes," but I might write it. In actual speech, the Q&A would go something like this:
Q: Is "OK" in use in British English?
A: Yes.
Q: What's the difference between "OK" and "all right"?
A: I don't think there's any difference.

I like TomJimJack's response and I would add that in the technical contexts in which I work, thinking "if yes" or "if no" is common.

Both "if so" and "if yes" could be seen as shortened versions of "if that is so" and "if the answer is yes."

OK comes from the Independence War and means 0 Killed

Guest - you didn't read the link I posted, did you?