[{"role": "user", "content": "I'm trying to express my regret about a past expense to an Italian friend, could you help me translate the sentence 'That cost us a lot' into Italian?"}, {"role": "assistant", "content": "The translation of 'That cost us a lot' in Italian is 'Quello ci \u00e8 costato molto.' You can use this sentence to express your regret about a past expense to your Italian friend."}]