Though you may travel through Greece using your GPS, it is always useful to be able to read the road signs and say them in Greek, when you may need some information from the locals. Herewith we provide a pronunciation guide for reading Greek.

VOWELS
Letters Pronunciation
Α,α a like in the word -a-lphabet
Ο,ο o like in the word c-o-re
Ω,ω o like in the word c-o-re
Ι,ι i l like in the word -i-diom
Η,η i l like in the word -i-diom
Υ,υ i l like in the word -i-diom
Ε,ε e like in the word -e-nergy

Diphthongs Pronunciation
ΕΙ,ει i like in the word -i-idiom
ΟΙ,οι i like in the word -i-idiom
ΥΙ,υι i like in the word -i-idiom
ΟΥ,ου oo like in the word b-oo-t
ΑΙ,αι e like in the word -e-nergy
ΑΥ αυ af like in the word -af-ter
ΑΥ,αυ av like in the word c-ov-er
ΕΥ,ευ like in the word -eph-emeroptera
ΕΥ,ευ like in the word -Ev-angelists

Each vowel of the Greek alphabet possesses only one sound, but different vowels may have the same sound.
The vowels O,o and Ω,ω are pronounced the same: like the o in the word organism.
Greek alphabet has three different letters, Ιι, Ηη, Υυ, as well as the three diphthongs (=pair of vowels), ΟΙ,οι, ΕΙ,ει, ΥΙ, υιwhich are all pronounced the same: like the i in the word idiom: Η Μυτιλήνη (EE mitiLEEni), οι Δελφοί (EE deLFEE).
The letter Ε, ε and the diphthong ΑΙ,αι are both pronounced as the letter ε = e (-e-nergy):Η αρχαία Σπάρτη (EE arHEaSPArti) (= ancient Sparta).
ΟΥ,ου is pronounced like oo (b-oo-t):ΗΝάουσα (EE Naoosa).
In some cases, the diphthong (=pair of vowels) ΑΥ,αυ is pronounced as af (-af-ter) and in other like av (c-ov-er):Το Ναύπλιον (ΤO NAfplion), but η Επίδαυρος (EE ePEEdavros).
The same goes for the diphthong ΕΥ,ευ. Sometimes it is pronounced as eph (-eph-emeral) and sometimes as ev (-Ev-elyn). Ο Ευρώτας (O EVROtas).

CONSONANTS
Letter Letter name Pronunciation
Β,β vita -v-iolet
Γ,γ gamma -y-es
Δ,δ delta -th-at
Ζ,ζ zeta -z-one
Θ,θ theta -th-eory
Κ,κ kappa -k-ilometer
Λ,λ lambda -l-ogic
Μ,μ mi -m-icrophone
Ν,ν ni -n-ike
Ξ,ξ xi -x-enophobia
Π,π pi -p-anorama
Ρ,ρ rho -rh-ythm
Σ,σ* sigma -s-ymbol
Τ,τ taf -t-echnology
Φ,φ fi -f-antasy
Χ,χ chi te-ch-nology
Ψ,ψ psi -ps-eudonym

Unlike the English B,b, the Greek Β,β, is pronounced like the English V, v (in the word verb). Η Μονεμβασιά (EE monemvasiA), o Βόλος (O VOlos).
Δ,δ is pronounced like the th in the word that, while Θ,θ is pronounced like the th in the word theory. Below are some examples of the pronunciation as th in the word theory. Η Αθήνα (EE aTHEEna), η Θεσσαλονίκη (EE thesaloNEEki), Here are some examples with the pronunciation of Θ,θ as th in the word that. Η Ρόδος (EE Rodos), η Επίδαυρος (EE ePEEdavros), ο ΆγιοςΔημήτριος (O AyiosdiMEEtrios).
English speaking people may confuse the Greek letter Χ,χ, which is pronounced like a heavy chi (similar to the ch in the word te-ch-nology), with the English X,x. The sound of the English X,x comes in Greek from the letter Ξ,ξ. Η Χίος (EE HEEos), but η Νάξος (EE NAxos).
Due to its resemblance to the English P,p the Greek letter Ρ,ρ, which in Greek is pronounced like the English r, may mistakenly be pronounced as P. The sound pf the English P,p comes in Greek from the letter Π,π. Η Ρόδος (EE ROdos), but η Πάτρα (EE PAtra).
Two consonants of the same kind are always pronounced as one: Ιωάννινα (ioAnina), Θεσσαλονίκη (thesaloNEEki).

PRONUNCIATION KEY
i (ill), ee (beer), e (ever), o (organ), oo (boot), y (yes), h (helium), th (theory), d (the). The capitalized syllables are accented.