To have a (bad) conscience about something - Avere la coscienza (sporca) su/di/per?

Question

It's the preposition that's the problem! I've found:

Avere la coscienza di/su qualcosa

and

Avere la coscienza sporca per/di qualcosa

but I can't find anything definitive in either case.

Thanks for your help.

Answer 1

As an Italian, I'd definitely say avere la coscienza sporca per [qualcosa], but it's always good to double-check and look for sources.

Google Books Ngram Viewer, from a purely “big data” point of view, seems to confirm that avere la coscienza sporca su is out of question, and avere la coscienza sporca per prevails, but seems to observe a significant presence of avere la coscienza sporca di too.

However, looking for examples of the latter construction one mostly finds that di refers to the person having the bad conscience. For instance,

la coscienza sporca di chi dimentica

or

si alzò con la coscienza sporca di un traditore

and so on.

On the other hand, there are also some examples where di introduces the thing the bad conscience is about, such as

Riccardo sapeva bene che questo era solo un tentativo di coprire uno scottante “affaire” internazionale, nonché la coscienza sporca di un evento passato e non un fatto di interesse nazionale

and

perché aveva la coscienza sporca di non averlo riconosciuto in clinica

The latter sounds unusual to me and, were I the editor, I'd discuss it with the author or translator, but this means that someone uses it. And I may well be wrong in criticising it: the Grande Dizionario della Lingua Italiana is not rich in occurrences of “coscienza sporca”, but one of them (third column), albeit in Roman dialect, is indeed:

Camilla, de certo, nun doveva avé fiatato, co quela coscienza sporca d’avé ricettato la merce, co tutti l'ori e le pietre

from no less than Carlo Emilio Gadda.