SImple suggestion for DuoLingo Review - mixed grammar review
I use Duolingo along with flashcards, reading, and conversation to work on my German. I especially like reviewing grammar with Duolingo—it seems to be the site's comparative advantage among other methods. The problem is that because all the grammar review lessons are clustered around a single tense/construction, the review is not as challenging as it could be. After a few questions, I don't have to discern context, I just follow the same formula to construct the sentences. No need to differentiate between present and preterite, because I know which unit I'm in.
I suggest that Duolingo simply make some kind of "review verbs you've learned so far" which mixes, e.g. conditional, past perfect, etc. This way, you have to decide which verb is appropriate. Seems like this would take very minimal work on the Duolingo end.
Thanks for an excellent tool—here's to making it just a little better!