Does "either" make an exclusive or?

Solution 1:

No, you cannot depend on that. If it were that simple, we wouldn't need clunky phrases like "exclusive or" to make clear when an "or" is exclusive.

Linguistically, "either" is simply a marker that warns you in advance that an "or" is going to follow. Nothing more.

Solution 2:

In everyday speech, "or" is usually exclusive even without "either." In mathematics or logic though "or" is inclusive unless explicitly specified otherwise, even with "either."

This is not a fundamental law of the universe, it is simply a virtually universal convention in these subjects. The reason is that inclusive "or" is vastly more common.

Solution 3:

Often, when people use "either ... or ..", they are trying to stress that they are expressing an exclusive disjunction.

But, not always.

Consider. I say "I want to be either rich or happy" ... I think that is a perfectly good usage of English ... but it is also clear that I mean this in an inclusive sense: it's not as if I go like "Oh, no, that's not what I wanted!" when I turn out to be both rich and happy. No, clearly I would be fine with that as well.

Probably the reason I use "either" here is because I may feel some tension between the two .. that being rich might well require hard work that prevents me from doing the things that makes me happy, or vice versa ... but clearly there is no certainty that I cannot be both ... and again, I would be just fine with both. So again, it's meant as inclusive, not exclusive.

The point is: English is super flexible, and super subtle, so there really is no hard rule here. You have to use your common sense to figure out what the speaker means in the context of when and where the speaker says it.