Apostrophe...

Noticed that a lot of people aren't sure when using an apostrophe to mark an ommison (missing letter) in a word when typing it as it's pronounced. Basically the apostrophe (') goes wherever one or numerous letters in a row are missing in a word or to mark. For example :-

What is up -> What's up -> 'Sup.
What is happening? -> What's happening? -> Wha's happ'nin'.
What are you doing? -> What'chu doin'? (Or wha'chu, same shit.)

Obviously it depends on how your character pronounces the words but they're just examples.

Secondly, using the apostrophe to indicate a possession. Here the apostrophe will go before the S that makes the noun plural unless the noun already ends in an S in which case the apostrophe goes after the last S. For example :-

Henry's chocolate.
Liam's cake.
James' pot noodle.

And of course you get some that overlap such as :-

Kareem's fat.

Could mean Kareem is fat or it could be referring to the fat that Kareem has.

Hope this helps, had to look into it myself after Lamont asking me a while ago how it was used properly so it should be pretty much right. Not really important but it looks much nicer if used properly rather than "Sup'? Chu' doin'?" Although Bain covered some of that aswell.