Inclusive and exclusive or
In talking recently about inclusive and exclusive or, I realized that the ambiguity about which kind of or is meant is often resolved in English through intonation.
For example, in Latin we could say
Ad cauponam imus; visne aliquid edere aut bibere?
(We are going to a restaurant; would you like to eat or drink something?) or
Ad cauponam imus; visne aliquid edere vel bibere?
(We are going to a restaurant; would you like to eat or drink something?). The distinction is that the first version assumes that eating and drinking something are exclusive and is asking which the listener would like to do -- would you like to eat something, or would you rather drink something instead? The second version allows for the possibility that both are true -- would you like to eat something, drink something, or both?
English has only one conjunction "or", but it has intonations that seem to convey pretty reliably whether it is used in an inclusive or exclusive sense. I'm not sure how to transcribe them here, but when I said them one after another, people understood which was which.
That means that English is less ambiguous than I'd thought. In general perhaps programmers' concerns about English being unlike formal logic are often dealt with -- at least in spoken English -- through intonations. For example, Latin also has "num" and "nonne" (or just -ne, kind of like the Portuguese né? or the Canadian English eh?, except that you can attach it to more places in the sentence), which indicate which answer to a yes-or-not question is expected.
Num soles carnem edere?
(You don't eat meat, do you?)
Solesne carnem edere? Nonne soles carnem edere?
(You eat meat, don't you?)
Although English does have ways of expressing this distinction, a lot of English questions don't seem to use a word that makes it explicit -- but intonations are available that can serve that role. And in speech, at least, those intonations can also serve to address the programmer's concern about double negation (which leads to the intution that "do you live here?" and "don't you live here?" ought to have opposite answers).
