Hi is the correct spelling pronounced "Hai" and it is the informal way to say hello. It is used among friends. Hey, is an informal way to ask for attention. It is rude to use this to strangers.

i think u mean HI:)) hi: is a greeting much used by Americans, and by people in e-mails. which means hello :))

I've never seen anyone write it that way, "Hy" Do you mean "Hey"?

lol when someone uses "hy" it's usually the warning signal that his/her English profiency is really bad. Of course sometimes it's just simple typo. Takes some serious lack of profiency to succeed in keeping to spell two-letter, one of the most common English words wrong...

Hi yes!