Please allow more variations on the answers!
I just had to quit a practice session because it was too frustrating ... there are so many translations that are not consistent within the course. For example, sometimes 미국 is America, sometimes The United States. The USA is not accepted at all for some reason (at least not in the exercise I am thinking of right now) and sometimes America is supposedly incorrect, sometimes The United States is supposedly incorrect.
I also just had an issue where "bicycle" was incorrect and "bike" was the correct translation when earlier "bicycle" was accepted in another task.
There also seems to be an issue with articles (the or a? If there is a way to know which one is correct, then it wasn't explained.)
Not to mention that very simple typos often lead to the answer being rejected. Duo is also super picky when it comes to word order. I mean, if the English sentence makes sense...?
I find this super frustrating because often it feels like I'm just trying to memorize a long English sentence instead of studying Korean.
Sorry for complaining so much but I really had to vent!
It's really difficult for beginners to do, because you have no idea whether it should be accepted or not. Whether it's a problem with you or with Duolingo. And no-one's answering the questions. The biggest problem I'm facing at the moment is topic/subject particles. It seems relatively arbitrary which it accepts. But maybe there's some hidden rule that hasn't been explained.
Translate into Korean: The house is not dark
집은 어둡지 않아요 - incorrect
Suggested answer: 집이 안 어두워요.
So you go, um. Is that a problem with using 은 instead of 이 or because of the verb? A few minutes later:
Translate into Korean: It is not dark here
여기가 안 어두워요 - incorrect
Suggested answer: 여기는 어둡지 않아요.
It's frustrating when it happens once every two/three questions and you don't know whether even wrong or whether you should be reporting it.
Maybe it's due to the nature of Korean, or because of the lack of take-up, but the course suffers from this more than I've seen in other courses.