What does yasou sagabo mean in English?

Answer 1

I think you probably mean Για σου σ' αγαπώ

or (roughly) ya'sou s'agapo

Ya'sou has several meanings, depending on where/how it's used. It is used as a "to your health" toast (similar to "cheers!" when you clink glasses). People greet with it (hi, hello). Among others.

s'agapo means I love you.

What you have here reminds me of the song from The Doors - Hello, I Love You. Maybe you heard a Greek translation?! :-)