Quotations are the repetition of words used by somebody in the past. When you repeat the speech or spoken words of a character from a play or novel, you are said to be quoting that character. Use of quotes requires quotation marks, speech marks or inverted commas to denote repetition.

Take the example of a lawyer who is trying to convince the jury of his argument in an essay. No matter how convincing he is, without evidence the jury cannot be completely influenced. The same applies to quotations, which like evidence convince the audience of the truth in your theory.

Therefore quotations have the purpose of backing a person