Apart from the typical use, the second person of verbs in plural is the politeness form in Greek and is very commonly used:

e.g.: Κυρία Αντωνίου, μένετεστην Αθήνα; (Mrs Antoniou, do you live in Athens?)

e.g.: Κύριε Πετρίδη, ξέρετε αγγλικά; (Mr Petrides, do you speak english?)