Hi Tatsiana! Yes, you are right. Those words are slang and are a contraction (combination) of other words. Wanna = Want to Gonna = Going to Gotta = Have to (comes from "have got to" / "got to") In writing, they should be avoided, unless it's an informal setting like an email between friends, a chat between friends, Facebook post, etc. Should not ever be used in a professional / formal setting in writing. In speech, I would suggest you avoid them but once you get more comfortable with speaking English you may find that just the speed you say the proper words creates these new words, and that's OK =) However if you're in a job interview, or talking to a teacher, or in a situation like that, I'd avoid using them.