This is the 70th most frequent Persian word.
ای
The Persian word "ای" means "O" or "Oh," used vocatively to address someone or something.
The word "ای" is used as a vocative particle to directly address someone, in this case, "friend".
ای دوست، مرا یاری کن.
Oh friend, help me.
The word "ای" here is used in the phrase "ای کاش," expressing a strong wish or desire.
ای کاش میتوانستم به گذشته بازگردم.
I wish I could return to the past.
"ای" is used as an addressing signal to attract the attention of the audience, in this case, "people."