To respond or tell the time in everyday conversation you have to use "Sono le..." (except for 1:00 am / pm and noon / midnight when you use "È...") and state the hour (l'ora), using the numbers from one to twelve.
Then, if it is past the hour, you can add the word "e" (and) followed by the number of minutes (for example, if it is 3:05, you would say "Sono le tre e cinque") or the word "meno" (minus) followed by the number of minutes until the next hour (for example, if it is 10:55, you would say "Sono le undici meno cinque").
In Italy, both the 12-hour clock and the 24-hour clock are used to tell time, and it is important to be familiar with both systems.
The 12-hour clock system is commonly used in everyday conversation and in situations where formal or technical language is not required. If it is necessary to clarify, we add "di mattina", "di pomeriggio", "di sera" or "di notte" (in the morning, in the afternoon, in the evening, in the night).
Examples:
6:00 am → Sono le sei di mattina
5:20 pm → Sono le cinque e venti di pomeriggio
9:00 pm → Sono le nove di sera
1:00 am → È l'una di notte