In Greek there are 7 vowels and seven consonants, 24 letters altogether. Each Greek word can be divided into syllables by the amount of vowel sounds in a single word:
αὐ-τός
aftos
this, him
βα-σι-λεύς
vasilevs
king,emperor

There are seven vowels in Greek: α, ε, η, ι, ο, υ, and ω. Also there is something called a dipthong, which is two vowels put together to make a single sound. In Greek they are:αι, ει, οι, υι, αυ, ευ, ηυ, and ου.

Finally, there are three improper dipthongs: ω-ι, η-ι, and α-ι, but instead of the iota being written on the line with the letter, it is written below and called the iota subscript: ῳ, ῃ, and ᾳ.

Vowel Length

The length of a vowel is very important in Greek. It affects the diacritic mark that is placed above it. For this, there are a few simple rules. The first is that ω and η are always considered long sounds. So if they are always long, ε and o, are always short. In addition, the diphthongs above are considered long except in one special case. An αι or οι at the end of a word is considered short: ὑποτάσσεθαι"subdued". Although an αις or οις is considered long at the end of a word. There are further rules for the length of α,ι, and υ, but they are too complex to be discussed here.

Breathings

In Medieval Greek there is something called a breathing. There are two of them, the rough breathing (ἁ) and the smooth breathing (ἀ).However, they make no difference in the words pronunciation and are merely there because Greeks are great traditionalists with their language. In Ancient Greek, though, the rough breathing represented a "h" sound when rendered into English: ἁρμονία for "harmony", while the smooth represented no sound at all: ἀναλογία for "analogy. Note: almost all words that begin with υ have the rough breathing except for a few such as upsilon. Also note: all words that a re lowercase and begin with rho have the rough breathing: ῥῶ.

Diacritics

There are three accent marks in Greek :
the acute: ά, over short or long
the circumflex:ῶ, over only long vowels
the grave:ὸ, over only short vowels

Every word in Greek has an accent. It must be learned as part of the word itself. All three marks represent an increase in the stress of the word's pronunciation. Thus in αὐτός, the αὐ- is heard higher than the rest of the word. All three marks have a complex set of rules which tell when they are used but here is a simplification: In each word there are three syllables on which the accent can rest. In βασιλεύς, βα- is called the antepenult, σι- is the penult, and -λεύς is called the ultima. Here are the rules in regard to the accent's appearance:

On the antepenult only one accent can appear, that of the acute, but only when the vowel of the ultima is short. Thus: ἄνθρωπος.

On the penult, there are only two possibilities, the acute or the circumflex. The acute is used when the ultima is long. Thus: ἀνθρώπων. The circumflex is used when the final vowel of the word is short. Thus: τοῦδε.

On the final syllable, the ultima, all three accents are used. The acute is only used over short vowels, and only when it is the last word of a sentence or followed by a pause as in a semicolon. The grave is used as a replacement for the acute over short vowels, when followed by a word. Finally the circumflex is used over long vowels only and has no further considerations. Thus: Περὶ τῆς Χαζαρίας, πῶς δεῖ πολεμεῖθαι καὶ παρὰ τίνων.
" Of Chazaria, how and by whom must be made upon it."(Constantine VII, De Adminstrando Imperio)

Remember that each word can have an accent place anywhere, but from that spot these changes must come.

Exercises

1. Divide the following words into syllables:αὐτός, βασιλεῖ, Καβάδης, εἶεν, ὐποτάσσεθαι
2. What are the seven Greek vowels?
3. What are the 8 diphthongs?
4. Which vowels recieve the iota subscript?
5. Is ω long or short?
6. Is eta long or short?
7. Is α long or short
8. In ὑποτάσσεθαι, is αι long or short?
9. In αὐτός, is αὐ long or short?
10. In ταῖς, is αῖ long or short?
11. In the following words classify the breathing:ὁ, εἶεν, ῥῶ, αὐτούς, Ἕλλας.

Each of the following words is displayed in different forms. The first form tells where the accent is. Change the forms for the changing vowels.
1. αὐτός, αὐτη, αὐτου, αὐτους
2. ἄνθρωπος, ἀνθρωπον, ἀνθρωπου, ἀνθρωποι
3. ὅδε, τονδε, τουδε, τωνδε