Why "Det ar regnar i dag" is not accepted?
You cannot translate word by word. There is no present progressive tense in Swedish.
Just translate it to simple present (presens).
Does " i dag" really need space?
It's accepted to both have the space there and not to have it. So no, it doesn't need the space.
DL needs the space. When I put 'idag'. She said 'Almost correct' , and said I miss a space.
We teach the variant with the space, it is considered more formal and correct.
Tack. So I can say it does not need the space but it is more correct to put the space.
Yes, sort of. It's preferred, but both are common and no one is going to look funny at you for not having it. :)
You still pass the question that way though. If we added it as "best answer", they would appear in multiple choice questions everywhere, and that would be no fun.
It us raining tiday should surely be Dat ar regnar i dag why is ar or is missing in your correct answer please ?