Okay, pay attention, take notes if necessary:

Yeah – an alternative, more casual version of “yes.” An affirmative. “Yeah, I remembered the soda.”

Yea – an Old English word, pronounced “yay.” “Yea, though I walk through the Valley of Rape and Despair . . . “

Yay – an expression of excitement. “Yay! You remembered the soda!”

Ya – an informal version of “you.” “Top of the mornin’ to ya.”

Then – used to illustrate sequence. “I bought the soda and then I went to the party.”

Than – used to illustrate difference. “The soda cost more than the chips.”

There – used to illustrate location. “Put the soda over there.”

Their – used to illustrate possession. “The party will be at their house.”

They’re – a contraction of “they are.” “I’m bringing the soda, they’re bringing the awesome.”

A – indefinite article used before words that begin with a consonant sound. “Hand me a soda.”

An – indefinite article used before words that begin with a vowel sound. “It would be an honor to hand you a soda.”

Its – possessive of “it.” Note that there is NO apostrophe. “Here is the car’s engine, and over there is its hood.”

It’s – contraction of “it is.” “It’s awesome that you brought soda.”

There’s lots more, so I’ll do sequels. Stay tuned.

I’m sure I’ll mention “Who” and “Whom,” but I’m still working on figuring that one out.