Είσαι όμορφη (for females)- Είσαι όμορφος!! (for males ... just mentioning :P)

Pronunciation : Ise Omorfi - Ise Omorfos
The capital letters show where the accent should be placed when saying the words. The "I" is pronounced as the "i" in the word "pit" .. the "s" in this case is pronounced as the "s" in "sock" (so an s sound not a z sound).

I love you - Σ' αγαπώ
Pronunciation: S' agap'O
Where the s again is pronounced as the s in 'sock' and the g is a soft g almost as the y sound you get when you pronounc words like "yogurt"