Greetings in Greek: yia sou, kalimera, efcharisto, with IPA

Γεια σου and γεια σας: hello, goodbye and your health

Γεια comes from Ancient Greek ὑγίεια, health, so γεια σου is literally your health. That explains its range: Wiktionary gives hello, goodbye and cheers for the same word, and Greeks say γεια σου on arrival, on leaving and when raising a glass. The short γεια alone works between friends.

The second word decides the register. Σου is your for one person one knows well; σας is your in the plural and the polite form for one person. Wiktionary's usage notes on these phrases spell out the rule: the singular is for family, friends, children and younger people, the plural for strangers and to show respect. Its examples show both uses of σας: Γεια σας, κύριε Γιώργο, hello Mr George, and Γεια σας, παιδιά, hello children.

Χαίρετε, the plural imperative of χαίρω, to be glad, is a polite greeting for hello and goodbye. Wiktionary notes that the singular χαίρε is not used as a greeting any more. Γεια χαρά is a casual hi and see you later.

Καλημέρα, καλησπέρα, καληνύχτα

The time-of-day greetings are built on καλή, good: καλημέρα joins it with μέρα, day, καλησπέρα with εσπέρα, evening, and καληνύχτα with νύχτα, night, all written as one word. Καλημέρα is said through the morning and doubles as hello; Wiktionary's example pairs it with the polite question Καλημέρα, τι κάνετε; Good morning, how are you?

Καλησπέρα greets someone in the evening. Καληνύχτα is said on parting at night, and Wiktionary's example adds a common companion: Καληνύχτα! και όνειρα γλυκά! Goodnight, and sweet dreams. Καλό βράδυ, have a good evening, is listed beside it.

Greek has a whole family of these wishes with καλή or καλό: καλή χρονιά for the new year, the form given on the Happy New Year in 122 languages page, and χρόνια πολλά, many years, which Wiktionary lists for birthdays, name days, the new year, Christmas and Easter alike.

Thank you, please and how are you

Ευχαριστώ is the first-person form of the verb to thank: I thank. Wiktionary traces it to Koine Greek εὐχαριστῶ. Ευχαριστώ πολύ is thank you very much, and in quick speech the word shrinks to φχαριστώ. A warm alternative is να ’σαι καλά, may you be well.

Παρακαλώ does several jobs. It means please in a request, you're welcome after thanks, can I help you? from a shop assistant, and hello? when answering the phone or asking someone to repeat. Its parts are παρα-, beside, and καλώ, call, and its ancient sense was to invite.

How are you is τι κάνεις; to a friend and τι κάνετε; to a stranger or several people, literally what are you doing? Πώς είσαι; and πώς είστε; are synonyms. On meeting someone new Greeks say χαίρω πολύ, I am very pleased; on leaving after the first meeting the past tense follows, χάρηκα πολύ, I was very pleased.

Αντίο, τα λέμε and other ways to say goodbye

Αντίο, from Italian addio, is the plain goodbye, with αντίο σου and αντίο σας along the same σου/σας line. In everyday speech γεια σου and γεια σας serve as goodbye just as well. Τα λέμε, we'll talk, is the casual see you, with θα τα πούμε for we'll talk later. Στο καλό, literally to the good, is another farewell that Wiktionary lists among the synonyms of αντίο.

A welcome follows the same pattern: καλώς ήρθες to one familiar person, καλώς ορίσατε to guests and strangers. The welcome in many languages table gives both the monotonic forms and the older polytonic spelling Καλῶς ὁρίσατε.

Common mistakes with greetings in Greek

The mistake that matters most with greetings in Greek is the register. Γεια σου to an older stranger, a shopkeeper or an official uses the familiar singular where Wiktionary's usage notes call for the polite plural; γεια σας is always safe. The same choice runs through τι κάνεις and τι κάνετε, καλώς ήρθες and καλώς ορίσατε.

Second, χαίρω πολύ belongs to the moment of meeting; when leaving after a first meeting, Greek switches to the past tense, χάρηκα πολύ. Third, παρακαλώ after a thank you is the expected reply, so answering ευχαριστώ with another ευχαριστώ misses it.