How can I tell when ~기도 하다 denotes alternatives? Can it have any other meanings apart from 'and' / 'also'?

Question

The most straightforward meaning of ~기도 하다 seems to be 'and' or 'also':

좋기도 하고 나쁘기도 하다 => it has both good and bad points

한국 전쟁은 "육 이오"라고 불리기도 한다. => The Korean War is also known as (the war of) "June twenty-fifth."

I have been told by a native speaker that it can sometimes denote alternatives, and this page on howtostudykorean.com has some examples:

저는 그 친구를 좋아하기도 하고 싫어하기도 해요 => I like that friend sometimes, and I hate him sometimes too

제가 나갈 때 가끔 향수를 뿌리기도 하고 가끔 안 뿌리기도 해요 => When I go out, sometimes I put on (spray) perfume, sometimes I don’t

These cases can be seen as alternatives, as they contain two opposite meanings - But as the howtostudykorean page suggests, you can still think of the function as additional : there are these cases, and there are these cases (similar to the previous 'it has both good and bad points' example).

I still wonder if some cases are ambiguous. For example:

자전거들 예쁘기도 하고 빠르기도 하다

Does this mean that all the bicycles are pretty and fast? Or could it mean that there are some pretty bicycles, and some fast ones?

If that case is not ambiguous, are there any that could be?

Answer 1

I think every sentence you mentioned are best interpreted using "also".

좋기도 하고 나쁘기도 하다: it is true that it is good, and it is also true that it is bad (in some other way).

저는 그 친구를 좋아하기도 하고 싫어하기도 해요: It is true that I like that friend (sometimes/in some ways), but it is also true that I hate him (in other times/ways).

Here's a contrasting example:

민지는 너를 좋아하거나 싫어하는 것 같다: I think Minji either likes you or hates you. (It is a possibility that she only likes you or only hates you.)

민지는 너를 좋아하기도 하고 싫어하기도 하는 것 같다: I think Minji both likes and hates you. (It must be the case that Minji has both feelings toward you.)

So, your last sentence can only mean "also":

자전거들 예쁘기도 하고 빠르기도 하다: These bicycles are pretty and fast.

(Since we just said "자전거들", it might be possible that we're only talking about some vague, different subsets of bicycles for 예쁘다 and 빠르다, but I think such an interpretation is pretty unlikely.)

If you want to say "some bikes are pretty and some are fast", you have to make it explicit:

어떤 자전거는 예쁘고 어떤 건 빨라요.