Could you please provide an example of this? Because I didn't understand what it is about.
I do not have an example because I have never taken Spanish. This is just what I heard(or maybe I misunderstood?). To my understanding someone told me that Spanish doesn't have cases but verb endings to show who is the subject(s) and who is the object(s). Like I said I am not positive about this because I have never taken Spanish before(and I never plan to).\

I'm not a specialist in Greek, but doesn't Greek has conjugations too?
Even though there are many roots having Latin origins in Russian I think Russian is closer to Greek.
Probably, and although another interesting topic, it isn't the point of this thread.

Languages aren't classified on similarity of words, but according to similarities in their grammars, since vocabulary borrowing changes much.
So are you saying the Romance languages are closer in grammar to Latin than the Slavic languages? If yes then how so?