babe i žabe

1. colloq. apples and oranges
   Ne mešaj babe i žabe, to su dve različite stvari. — Don't mix apples and oranges, those are two different things.
   Porediti ta dva telefona je kao porediti babe i žabe. — Comparing those two phones is comparing apples and oranges.

Usually used with the verbs mešati, porediti, sabirati (to mix, compare, add up).