还是 and 或者: exclusive and inclusive disjunction

This is a little topic that’s been bugging me for a while. There’s a well-known distinction between the words 还是 and 或者 in Chinese, both of which are simply “or” in English.

The usual explanation and one that generally works fine is that 还是 is for questions, 或者 is for statements. Fair enough, except there are exceptions to both of these. First up, a question with 或:

你想出去喝几杯或吃个饭吗？ Nǐ xiǎng chūqù hē jǐ bēi huò chī gè fàn ma? Would you like to go out for a drink or something to eat?

OK, so it might be a little bit unwieldy but it makes the point. Now, this is fairly easily explained by saying that the 或者 actually is in a statement here. The question is about whether that statement is true or not. So the “或者 is for statements” explanation still kind of works.

But you can also find statements with 还是 meaning “or”:

不管你同意还是不同意，我还是要做。 Bùguǎn nǐ tóngyì háishì bù tóngyì, wǒ háishì yào zuò. Whether you agree or not, I'm going to do it.

So, the statements / questions distinction isn’t actually quite right. A more accurate explanation seems to be that the difference is between inclusive and exclusive disjunction. This is the difference between “and / or” and “either … or” in English.

As you can see, English just doesn’t have a good way of expressing inclusive disjunction. We have to use the clumsy “and / or”.

So 还是 is for “either … or”, when it can only be one thing or the other, not both. And 或者 is for “and / or”, when it could be one thing, the other or both. They’re just words for exclusive disjunction (还是) and inclusive disjunction (或者).

But then you come across a sentence like this:

我通常骑自行车或乘公交车去上班。 Wǒ tōngcháng qí zìxíngchē huò chéng gōngjiāo chē qù shàngbān. Usually I get the bus or ride a bike to work.

I have to say that threw me a little bit at first, as it seems like it ought to be exclusive disjunction (还是). Presumably this person does not mean that sometimes they both ride a bike and get the bus to work, so what’s the “and / or” word 或者 doing there?

I think the explanation is that this sentence doesn’t cover one event, it covers what the person does usually. So, it makes sense it includes both options. The problem is actually with “and / or”, which isn’t exactly the same thing as 或者, it seems.

Gah, logic.