Hello in Greek

The everyday Greek hello is γεια (ya) — one syllable, said with a smile, and used at any time of day. You will also hear the fuller forms γεια σου (ya sou) to one person you know well, and γεια σας (ya sas) to a group or to someone you address politely. It comes from the word for health, υγεία, so greeting someone is literally wishing them good health.

Which form to pick comes down to the same choice Greek makes everywhere between friendly and polite. A waiter, a shopkeeper, or someone older gets γεια σας; a friend, a child, or a peer who has already been chatty with you gets γεια σου. Plain γεια on its own is fine in passing, and it doubles as a casual goodbye, the way "ciao" works in Italian.

If someone sneezes, you can also use the source word directly: γείτσες or με τις υγείες σου, again wishing health. Health runs through Greek politeness — you will meet it again in the toast γεια μας ("to our health") when glasses are raised.