"I am in the bathtub."
Translation:Jestem w wannie.
if after w or f there is another consonant we say "WE", if it is vovel , we say "W" w Warszawie, we Wrocławiu, w Finlandii, we Francji
also we is before mnie, which is exception for ze, and ode as well
also in some set phrases and before some nouns (we Lwowie- in Lvov, we śnie - in dream)
Well, exactly as immery wrote, "in Lwów" and "in a dream".
Mój dziadek był ze Lwowa.
Firstly, 'było' is neuter, so it only makes sense to use about a person if the word you're using with it is 'child' or 'baby'. And then, firstly you need Genitive for the name of the city, and you use 'ze' instead of the usual 'z' because it would be very hard to pronounce.