Help with Greek letters!

[cebep]

Please someone tell me what is the difference between these letters because they pronounce the same, but is there any rule on when to use one instead of the other?

Ο ο and Ω ω
σ and ς
Η η and Ι ι

Thanks

[kreatza]

well that's a good question) from what i saw( being a self didact in what concerns greek language) i saw that "σ" is written like this at the start or at the middle of the word, and like this "ς" at the end...
But i told u, this is a thing that i noticed We must wait for a better reply) a smarter one:P
bye

[MoonRiver]

what kreatza said is right, 'σ' is the first letter of the word or it's in it, and 'ς' is the last letter of the word (if this is a 's', of course)
you pronounce them the same way

the other letters I don't know, I'm not Greek and only speak 5 words of it (I'm trying to learn it)

[Aetos]

Kreatza was right with the σ and ς, the rest im not too sure, lets hope we get a reply soon.