Hmmm, thinking about my dialect of English (Lancastrian) I can certainly say else without an or and it doesn't sound unnatural to my ears. Something like "if you're hungry now then I can make you a sandwich, else we'll eat when we get to the pub" doesn't sound more awkward than using otherwise. I can't say whether that's just because the Lancastrian dialect preserves quite a few old fashioned usages that have fallen out of use in "standard" (i.e. southern posh) British English and American English, whether it's common usage in other dialects of British English, or if its just because I'm a programmer. Going to go ask some English teachers!
The consensus amongst the three English teachers I asked was that it should be "or else" or "otherwise" and that it's probably ungrammatical, although none of them could explain why. The one who is also an actor said "it works as a line" and she wouldn't think twice about it in a script or as written dialog. Interesting one though!
Funnily enough, to me "what else" sounds more like "what would you like to do in addition" as opposed to "what would you like to do otherwise".
Certainly in Australia, "anything else with that" is quite common in shops, particularly in food shops, or pubs. Or at least it used to be be when I was there.
Sure, but if you ask for A, B and C and someone asks "what else?" then they mean "what about things that aren't A, B or C?" It's still the same basic meaning, set complement, but about things rather than logical states.
The question isn't so much whether "else" is used at all, but rather whether it's used as a conjunction. That's why the article author mentioned "or else": here "or" is the conjunction, so that proves "else" isn't fulfilling that role. In this example you gave:
> What else do you want to do?
"else" is acting like a noun rather than a conjunction (compare with "what activity do you want to do?).
Works in my genericsSouthern British english dialect too. Think it might have been dropped in American english where it might be considered quite formal.