Grammar School

[Tomahawk]

The apostrophe indicates something plural, correct?

No.

Dio's bong is huge! or Thats Dios bong.
The second sentence should have an apostrophe?

It should have two.  The first sentence above is correct, but the second should read "That's Dio's bong."
The apostrophe is used for contractions, as in the first word, and to indicate posession, as in the second.

What designates in a sentence that an apostrophe goes on the end of a word?

An apostrophe usually goes at the end of a word to indicate possession of something which already ends in "s."  For example:  That's Diomedes' bong.  You don't want to write "Diomedes's bong."  That would be incorrect.

Sometimes the apostrophe is used to indicate that the word has been truncated, either at the beginning or at the end of the word, usually to write slang or colloquialism:  Bring that baggie over here, 'cause we need to re-pack Dio's bong somethin' fierce.

I type words like gonna, wanna, gotten and 'cause, mainly 'cause that's the way I talk, and I don't necessarily try to sound like somethin' I'm not. Novels I read quote the characters in them the same way to add realism to the book. If they were all quoted in perfect English, it would make for some boring novels.

fixed

Nice post. Pure quality.