"Are you coming tomorrow?"
Translation:Kommer du i morgon?
The suggested answer (the one you see on top of this page) should of course always be accepted. If it isn't, there's a bug somehow. If someone can share a screenshot of this with us, we can report it to Duo staff.
There's a known problem with spelling variation for i morgon and imorgon where it says Imorgon is a typo (it isn't, that's also correct) that we have already reported, so we don't want screenshots of that. But if you don't get the literal suggested answer accepted, please share a screenshot.
Forum post about i dag/idag bug: https://www.duolingo.com/comment/12941839
This is very interesting and it is great to learn how the language evolves. I took my first Swedish classes at school in the 1990s and this wasn't a common way to say it those days but yes, the languages do change and the spoken language sometimes slowly oozes into the written language, too.
English has two present tenses, the simple present comes and the present continuous is coming. Swedish only has one present tense, kommer, so it covers both those.
In the future tense, we could say either ska du komma or kommer du att komma – in both cases with the infinitive komma, not the present tense kommer.