what would be the singular for kocky?
But in a sentence like this, it would be "kočku," because it would be in the accusative case... just to confuse you a little more. :-)
Isn't Frantisek a man?
Yes (or he might be a boy -- either he or Matěj is in another sentence...). But man or boy, he must have kidnapped Žofie's or Kateřina's cat!!!