We Need to Talk

The following words are NOT the same and they are NOT interchangeable with one another:

Yeah
Yay
Yea

Yea means yes. It's the opposite of nay as in: "Do you want to win the lottery? Yea or nay?"

Yay is an interjection of joy as in: "I just won the lottery. Yay for me!"

Yeah also means yes as in: "Did you just win the lottery?" "Yeah, I did."

I say yay for those of you that regularly choose the right one.

Yeah, I did.