"Che ora è?" or "Che ore sono?"

these are the questions we ask when we want to know what time it is.

              

              

Notes

• the definite article le (or l´- with "una") is always used (because le ore is feminine plural)
• it is not necessary to use the word "minutes"
• it is also possible to tell the time in digital form: sono le quattordici e quindici (14:15), especially in official and public contexts
• the word ore is used only (mostly) in official and formal situations, like invitations or official announcements: La festa comincia alle ore sette. 
• it is also possible to say mezzo instead of mezza, but mezza is correct (because mezza ora - feminine)
• un is always used with quarto
• at midnight - a mezzanotte
• at midday - a mezzogiorno

prepositions