When Should a Translator NOT Translate?

Ponte Vecchio, Italy

What makes language and conversation beautiful? When does NOT translating actually contribute? When does it help to retain a few native words or phrases in your conversation?

When should one leave in a phrase or two; a well-known word or two that captures the essence of the moment, a je ne sais pas, or for some Italians another colloquialism, Non ci piove?

Zack Rogow discusses this in a post and discussion at Intralingo.
Follow along to see what he shares about this topic from his experiences in translation: