you are wrong to mark the questions wrong if there are more than One way to say it in English.
A lot of the examples you are giving have more than one way of saying the sentence correctly .
Catherine is right. Plus, there is a feature meant for this: in such cases, if you hit "Report" then "My answer should be accepted", the course contributors receive a notice, and may very well add your solution. You then get an email to notify you, happened to me a number of times. Remember, course contributors are human beings, most of the time volunteers at that, they can't possibly think of everything.
Keep on your good (excellent, seeing your levels) work, and make the course better for everyone :)
Hi, dear Catherine. I should live up to a childhood dream, actually, by beginning Esperanto. I gave it a try a while back (I had hit a plateau in German a few weeks before the rolling out of crowns, and got demotivated — direct tree, reverse tree and laddering through English — so I needed a diversion), and liked it.
Plus I think it will take me through the phase of going out of Duolingo for German — moving on to real life material — without being too daunting. I'm so far from fluency, but someday, the dearest little green owl will have nothing more to teach me, and I'll have to try my own wings, yet I don't want to go :)
It is a difficult task for the course constructors to get all the translations right of the first go. If you know you are right, then say so, and your input will be checked and added.
It's true. I marked "toll" as "cool" and was marked wrong. I took German for six years in school (and am relearning it), and I know toll means cool. I had to stop challenging myself by using the keyboard so I didn't get more wrong.
Often, yes :) The worst I've seen is being called wrong when I actually used a more elegant version of what was considered correct. The cringing is hard ;) But really, they do read those report and take them into account.