While they write, I often see people make mistakes like the following:

Peter: "Hey, do you want to go to the library with me?"

Quinn: "Yea, I will meet you there at 3 pm."

Will Peter meet Quinn at the library later? Maybe, but Quinn meant to say "yeah," not "yea." How do I know? I know because "yea" is pronounced like "yay." Knowing the pronunciation, read the above conversation over again. Sounds silly now doesn't it?

The archaic form of "yea" indicated

a) affirmative
b) indeed

or

c) not only that, but this as well

"Yea" is now only used in voting to indicate an affirmative vote, or a vote in favor (instead of opposed). The following sentence is a correct way to use "yea:"

Peter: "Where do you stand on the issue of wanting to go to the library with me?"

Quinn: "Yea."

or

Peter: "Do you want to go to the library with me? All those in favor say 'yea,' all those opposed say 'nay.'"

Quinn: "Yea!"

Alternatively, the conversation could proceed as follows:

Peter: "Hey, do you want to go to the library with me?"

Quinn: "Yeah, I will meet you there at 3 pm."

Now it's a library date!