Contractions of auxiliary verbs, negatives, and in questions with is; are used in everyday spoken English by all sections of British society.
Students often ask me if I ever use contractions such as gonna and wonna in my own speech. At first I said No, I don't use such terms. I always say "going to" and "want to".
We are going to listen to different English accents and listen to how weak words are pronounced. Weak words are words that are not stressed when we speak, they are the words that we say quickly and so it often sounds like they disappear as all the expected sounds can not be heard.