Yeah... anytime I see a "了" in these sentences, I report them when the English translation is in the present tense, because... to me... the "了" is the equivalent of the "-ed" at the end of English verbs.
Yeah, a lot of the grammar seems iffy...like not being able to use certain measure words in the Chinese translation, not being able to use regional variations, or words with ambiguous meanings. Taking Chinese Duolingo out of beta will definitely be a challenge.
After you get marked wrong, there should be a "報告問題" button under the correct answer. Click on that and report what problems you see!
I think this way is easier on the moderators, so that they don't have to go through the forums to see what other people suggest as the correct answers.
hmmm.. not exactly, sometimes it means nothing. Take this "我要去北京了" - "I'm going to Beijing". There's no "-ed" in the sentence, but "了" makes sense.
Yeah, I understand what you are saying. Words like 的 and 了 oftentimes are there, because otherwise the sentences would sound unnatural. I'm just a strict literal translator (when I can get away with it) on Duolingo, so I would rather have 了 only match up to the English "-ed"... since I personally think that it's easier to associate "-ed" with 了 when Chinese learners bump into the English past tense on Duolingo. And... it's also because I'm OCD about consistency. Ha ha.