Comparing the following sentences, what are the differences between them?
Cosa sapresti dirmi su Luigi Rossi?
Cosa sai dirmi su Luigi Rossi?
Since it is a question, I don't see any difference between those sentences. Furthermore, I don't see any reason to prefer the conditional to the indicative mood.
Is there any difference between those phrases?
Does the first, for example, imply any willingness from the person who answers me? Is it a more polite way to ask a question, since it would be understood as Cosa sapresti dirmi su Luigi Rossi, se mi volessi rispondere?