@bonas.kneck, yes, in theory, the incorrect options in an exercise could be incorrect for any reason. In practice, I don’t think there are many exercises where the incorrect options are grammatically incorrect themselves (e.g. misspelled words or incoherent sentences). That’s probably a good thing, since many people actively learn from the incorrect options as well, like you do. I’d say you should keep taking a look at the incorrect options in an exercise, even after spotting the correct option. Whenever you’re in doubt, you can always reach out via the “Send direct feedback about this question” button. Meanwhile, from our side, we will continue to quickly and frequently make any necessary changes to exercises to improve everyone’s learning experience.