Why för and not om?
Same question, as well.
"du dig" .. you you?
I word-for-word translate it as "Why do you worry yourself about it?"
In Swedish "att oroa sig" - "to worry" is a reflexive verb.
can somebody explain why "why do you worry about THAT" is wrong? doesn't 'det' mean 'that' as well?
It's not. My answer of "Why are you worrying about that?" was accepted, so report it if it still isn't accepted.
Why is ‘upset yourself about it’ not acceptable instead of ‘worry about it’?
"Why are you worrying yourself about it" was not accepted. Is this too Northern England regional? ;)