Grandson and nephew are the same word? Is there a different word that would distinguish it?
I think there isn't. In Italian is the same: "nipote" works for both "nephew" and "grandson", but also "niece" and "granddaughter".
I don't understand a thing. Wikitionary says the Dative-Genitive of "femeie" is "femeii". So why is it "femei", here?
for the definite articulation yes, but here femeie is indefinite (you'd say această femeie, not această femeia)