[{"role": "user", "content": "I've come across the English expression 'That'll be the day' and I'm wondering, how would you translate that phrase into Italian, especially considering its idiomatic meaning?"}, {"role": "assistant", "content": "The English phrase 'That'll be the day' is an idiomatic expression that conveys skepticism or doubt about something happening. The correct translation of this phrase into Italian is 'Quello sar\u00e0 il giorno.' This Italian translation maintains the same idiomatic meaning as the original English phrase."}]