Another word order question... Since the plural nominative ending and plural accusative ending of both of these words are the same, how do I know whether this means "Do you cats eat flies" or "Do your flies eat cats"? As nonsensical as the latter seems, I need to know this for future reference.
Well, there are some scenarios of what can happen:
1) You either manage to use a completely different statement that avoids this problem or
2) sometimes you can use the passive voice (which can sound a little stiff) like:
Mrak zakryl měsíc (The cloud covered the moon / The moon covered the cloud.) → Měsíc byl zakryt mrakem. (The moon was covered by the cloud.) (not really used in spoken Czech.)
3) You say the ambiguous sentence and only then realize that it is ambiguous and the other person doesn't get it. After that you quickly start explaining what you meant (often using a lot of pronouns and wildly gesturing while the other person nods and smiles stupidly the whole time).
Out of these, I would say the third one is the most common :-). But again, when a situation like this happens, in most cases the context makes it clear what you mean so it's not a big deal.