I'm looking for a clear definition, examples, differences and explanations of some of English language styles such as: officialese, official, formal, informal, neutral, slang, colloquial and taboo. Please help me with this.Thank you very much.
A good learner's dictionary such as the Oxford Advanced Learner's Dictionary or the Longman Dictionary of Contemporary English will tell you a lot about such things. Buy a copy of one of them. Wish you all the best.