Thank you for this explanation! I have been playing Duolingo on my phone and thus couldn't see conversations when man en vrouw were introduced. I only just now learned from your comment about the husband and wife meanings, and when it is applicable.
It would be nice, if these are important meanings, to force them as answers in a couple of questions in the first introduction of those words. (The app doesn't show things like "this would be another translation" when you select or type a variant answer.)