Marked as wrong for "Anna writes more slowly than Tom" (which is correct), and given solution of "Anna writes slower than Tom" (which is incorrect).
This is because "slower" is an adjective (ie, used to describe nouns), whereas "more slowly" is an adverbial construction and is what is needed here (as we're describing the action of writing, not Anna per se).
Fixed. I think we should still accept "slower" because I definitely saw that used.
"slow" is down as an adverb in the dictionary so "slower" is also adverbial.
I'm reviewing this section and finding many, many more sentences than there were the first time I worked through it -- and I mean this in the best possible way. Thank you to all of you who are adding content and helping the rest of us learn Russian!
Actually, we have not added that much since the launch of the course in early November 2015. It is just that Duo automatically gathers statistics and mostly gives you sentences users have least trouble with. For example, Это быстрая песня is offered about three times as often as Мы знаем много песен.
The system makes your life easier but ultimately may leave the impression that some lessons lesson have, like, 5 or 6 sentences while in reality they have dozens.
The only correct translation is "Anna writes slowlier than Tom". "slower" is an adjective and should not be used in this case, while "more slowly", even though possible, should be avoided since the (more) correct form for the comparative is "slowlier".
No, "slowlier" is not a real word. It is not present in the Oxford, Cambridge, or Merriam-Webster dictionaries and has less than 20k results on Google. I can see your logic, but it simply is not used.