Remember that to say please or you're welcome in Greek, you say Παρακαλώ (Parakaló).
To ask if someone speaks Greek, you say Μιλατε ελληνικα? (Milate ellinika?).
It sounds like mee-lah-tay ay-lee-nee-kah

In the Greek language, the word for Greek comes from the story of Helen, the father of all of the famous rulers of Greece.
Other languages like English call it Greek, because of some other tribes of people that have lived in the area, that called themselves Greek.
To say yes you would say Ναί (Naí) which sounds like nay

or to say no you would say Οχι (ochi) which sounds like oh-xhee

Yes and no can be tough for English speakers to remember, because Ναί (Yes) sounds like no, and Οχι (No) sounds kind of like OK.
The letters for these new words are:
Μ (Mu) ι (iota) λ (lambda) α (alpha) τ (tau) ε (epsilon) ε (epsilon) λ (lambda) λ (lambda) η (eta) ν (nu) ι (iota) κ (kappa) α (alpha)?
Ν (Nu) α (alpha) ί (iota)
Ο (Omicron) χ (Chi) ι (iota)

(from: wikipedia - center for the greek language)
ASL: Do you speak ASL?
Italian: Parli italiano?
German: Sprechen Sie Deutsch?
Spanish: ¿Hablas español?
French: parlez-vous français?