My inlaws are Finnish... the total lack of germanic/romance cognates makes it very difficult for me to remember any vocabulary. But I've never really put in a serious effort to learn it.
Greek is also very synthetic, so a little basic vocabulary goes a long way. I like the word for "waterproofing", literally "against-through-rain-making" (αδιαβροχοποίηση, a-dia-brocho-poiesi)