We've learned how to read Greek, but how do we know which one of the syllables we
need to give emphasis to? In other words, which one of the syllables sounds louder?
In the Greek language there is a little sign just like the single quotation mark, that tells us where we will pronounce the syllable louder. This sign is called an accent = ο Τονος.
The Greek accent is symbolized like this: ΄
The accent (ο τονος), goes only on top of Vowels, and only the
last three syllables of a word can take an accent.
πατέρας (father), μητέρα (mother), αυτοκίνητο (car), οικογένεια (family).
You think you have it bad? The story is that before the 1980's there were three accents used in the pronunciation of a word. Fortunately, that changed, if I remember correctly, in 1979.
The Double Accent
The Importance of the Accent
Simple Spelling Rules