Translation:Tomorrow is Thursday.
I'm a native Chinese speaker. 明天是星期四 would be better. 明天星期四 sounds like Tomorrow, Thursday (For emphasizing.) Sometimes 明天星期四 means Tomorrow is Thursday. That's for answering a question. Q:明天星期幾? A:明天星期四。
I keep typing 'tommorow' instead of 'tomorrow'. I know this, but can't duo have a little leeway for typos?
I don't know about this course, but you usually/often get one typo (such as transposing two adjacent letters) allowed in other courses (provided it does not create another valid word) but yours has effectively two typos and the computer algorithm cannot cope with that. The computer would lose the plot trying to keep track of all possible multiple-letter spelling errors and differentiate them from actual mistakes. That would be almost impossible.
However it would be possible for the moderator to allow your misspelt word if they thought it was a common enough error, but even then they would have to allow everyone else's common spelling errors for every word .......aaaargh!
I said "will be" instead of "is". I think my response should be considered correct...