Wassup is another way of saying "What's up". You can also say Wazzup.
"Not much, dude"
A term typically used to describe a very, very ugly person. People always say it at my school. There is usually a lot of emphasis on the "Life" part, so you say it like "Ugly as LIIIFE!!!!"
Dude that girl is UGLY AS LIFE!!!!
People usually say "Oh SNAP!" as an exclaimation, and it can be either positive or negative.
Positive: "Oh SNAP i aced the test yo!"
Negative: "Oh SNAP i forgot to pop the popcorn!"
"Dude" is a word that tons of people use for tons of things. Anyone can be called "dude", even if you are a girl. It can be used in so many many ways in so many situations and it can still make sense.
"Hey, dude, wassup?"
"Dude, that was so awesome!"
(and there are infinite other examples)
O shit is pretty much the same as saying shit, but it is like realizng something thats bad, and then saying, O, SHIT!!!
O shit, I got my gf pregnant!
WTF is the abbreviation for "What the Fuck", though it can also be for who, where, why, when the fuck. People usually put "?!" after WTF, or they just put a question mark. People usually say WTF when they are really shocked by something, that is crazy or really weird or its just a WTF moment.
Dude 1:"Dude, guess what? I killed a dude for no reason"
Dude 2: "WTF?!??! What is wrong with you dude?!?!?"