"My grandfather is looking for a lamp."
Translation:Mój dziadek szuka lampy.
The polish "genitive" (dopełniacz) is like a case for things that are missing (or belong to something - which would be our understanding of genitive). And when you're looking for something you don't have it. So you use "lampy" instead of "lampę". That's at least the way I understand it/explain it to myself.