I didn't noticed before, but it seems like the question pronouns in swedish are also cognates with most of the PIE languages (probably via the *kw phoneme):
-vem (sv) -who (en) -quien (es) -кто (ru) Etc
I guess, if this is true, that the kw phoneme became wh in proto-germanic, and then *w>v in old norse? Sorry for not using the phonetic symbols
I'm sure I've seen 'vilka' as a translation for 'who'. Eg. Who was in town today? Vilka var i stan idag? Is this wrong?
In fact my very next question was 'vilka läser böcker' so it feels like vilka should be accepted as a translation for who in this question.
Definitely, added it. In Swedish, we can distinguish between singular 'who', vem, and plural who, vilka.