I live in Paris or in France
Read the title of this post. What do you think about it? Is it a good sentence? Can you imagine someone saying it? Probably not, right? Although grammatical, it's a weird sentence to say.
These type of sentences have been around for fifty years, ever since the linguist James Hurford wrote his paper "Exclusive or Inclusive Disjunction." In his paper, he identified the following generalization, later dubbed as Hurford's constraint:
If we have a sentence of the form "X or Y", if X entails Y or vice versa, the sentence is considered odd.
But is this always the case? Consider the following sentence:
She ate some of the cookies or all of them
Although eating all of the cookies entails eating some of them (Y entails X), this sentence is perfectly fine for native English speakers! Hurford's constraint does not apply here.
While these are cool observations, they only try to generalize the situation, rather than explaining it. Why is it the case that if one part entails the other, the sentence is odd? What in our minds is prohibiting this situation? Why in some cases is it not the case? These are all open questions! (and a quite active topic of research in linguistics).
I think this is a really interesting topic since it captures some of the challenges linguistic research is about, while still being approachable enough for non-linguist people to understand. I hope to write more about it, as it really interests me these days.