Here's one guy's take on it: http://forvo.com/word/tr%C3%B6jorna/#sv It's hard, at first, to hear sounds that don't exist in your native tongue. Your brain wants to tell you which normal sound it almost aligns with, rather than telling you what it really sounds like. I thought Swedish ö usually is /øː/ or /œ/ which are sounds that don't exist in my dialect of English. I think they require rounding your mouth and protruding your lips while making a "u" like in English put. I think when we have heard Swedish "beef" in Duolingo: "nötkött", we heard ö as /øː/ and then ö as /œ/ in the same word. I think we have to hear many repetitions, maybe from different speakers, to get comfortable with it. To me, the TTS of tröjarna did not sound like the ö in nöt. The Forvo did not either. I requested another pronounciation. Maybe it changes sounds when preceding a 'j'? I think it can change before an 'r'. I played a sample recording of Swedish and you hear "överens" use /ø/ and "försöket" use both /øː/ and /œ/. I tried a Swedish newscast recording and they sounded different than a Swedish audiobook. I don't think we really should try to master the pronounciation yet. Better to grind through lots of exercises :)

Just the way Swedish is. The spelling de/dem is a bit antiquated, but kept anyways.

The spellings mig/dig/sig are also a bit antiquated, pronounced as were they spelled mej/dej/sej.

"jumper", or the plural here, is usually accepted. If you find a sentence where it's not, please do report it.

Are you referring to å, ä, and ö? Because if so, you really need to stop thinking of them as accents - they're individual letters in their own right. An "ä" is as different from an "a" as a "b" is from a "d". And there are many occasions where you really don't want to mix them up - for instance:

• höra = hear
• hora = whore