"I hate waiting for lunch."
Translation:Nienawidzę czekania na obiad.
Nope, wrong case. Nienawidzę kogo? czego? = Genitive.
The infinitive should work though: "Nienawidzę czekać na obiad".
"Imiesłów" ;) No ę this time. Also this is not imiesłów, imiesłów is a verb having characteristics of an adjective or an adverb, not a noun. This is "rzeczownik odczasownikowy" (I guess English 'gerund', coming from Latin, is an easier phrase).
I don't really know, but my guess would be the infinitive.
Thank you! I have had that wrong idea in my head for a very long time. Now I know the difference. :)