"He did not answer my question."
Translation:Li ne respondis mian demandon.
Mi konfuzis Esperanton kun la germanan!
Mi skribis: "Li ne respondis mian fragon."
I think I'll forgive him for not answering my strawberry XD
Ne ŝtelu dumajn fragojn! :) (Germans will understand "do not steal during-ish strawberries" as "do not ask stupid questions".)
It won't accept "Li demandon mian ne respondis." Are postpositive possessive adjectives and SOV not allowed?
Allowed, yes, but developers have to add all accepted translations manually, and so they cannot really add all grammatically possible permutations of words.
In general, stick to adjective-noun and SVO word order on Duolingo. When writing poetry or talking freely, you can be a bit freer but here on Duolingo, have compassion on the course maintainers....