Currency and card terminals
Greece is on the euro. Cards are widely accepted, including in most tavernas and shops. For transit, buy an ATH.ENA ticket or ATH.ENA card from the machines or ticket office rather than assuming you can tap a foreign bank card at the gate. Wherever you do pay by card, expect the terminal to offer to bill you in Canadian dollars β always decline and choose euro. That 'dynamic currency conversion' rate is set by the terminal operator, not your bank, and it is always the worse of the two.
Cash, ATMs and tipping
Keep small notes for street carts, periptera kiosks, church donations and older tavernas. Use ATMs physically attached to a bank branch; the standalone machines in tourist lanes stack their own fees and push their own conversion. Tipping is not obligatory and staff are salaried β rounding up or leaving the coins on the table is the norm, and a service charge is not usually added to the bill.
Language
Greek, written in the Greek alphabet, and romanised spellings on signs vary wildly for the same place, so Monastiraki, Monastiraki and ΞΞΏΞ½Ξ±ΟΟΞ·Οάκι are all the one station. English is widely and confidently spoken in central Athens and by transit staff. Learning to recognise ΞΞΞΞΞΞ£ (exit) and the station names in Greek capitals saves more trouble than learning phrases.
Power
230 volts, 50 Hz, with Type C and Type F round-pin sockets β the standard europlug shape. Phone and laptop chargers are dual-voltage and need only the plug adapter. Canadian appliances that are 120V-only, which usually means hair dryers and styling tools, need an actual converter, not an adapter, or they will destroy themselves.
Tap water
Athens tap water comes from EYDAP, meets EU drinking standards and is fine to drink β bring a refillable bottle and use it. This does not generalise to the islands: on many Saronic and Aegean islands the supply is desalinated or trucked in and locals themselves drink bottled, so ask when you get there rather than assuming.
Scams and safety
Global Affairs Canada flags petty crime and pickpocketing on Athens public transport, and the hotspots are exactly where you will be: the airport train on Line 3, and the crush at Monastiraki and Syntagma. Organised groups work in pairs with a distraction. Separately, ticket validation is enforced rather than nominal β a bought but unvalidated ticket counts as no ticket, and the penalty is calculated as a multiple of the fare. Demonstrations cluster around Syntagma and on set dates including 1 May and 17 November, and can close metro stations at short notice.