Slang : Slang can be used to shorten words or talk to different groups of people. For example, If I was with my friends I would talk in an informal way in front of them, as if I were talking to someone of a higher status I would talk in a more formal manor.

Omission: An Omission can show where missing words or letters in a word were. In any given case, if I said I’m instead of I am that would be omission.