I don't understand when to use reported speech. Can you explain it?

Reported speech or indirect speech is sometimes used in German to convey what someone else has said. It is not commonly used in spoken language, but instead mainly in journalism, in order to distance the author from a quote that they have included in their article. This can be a useful way of casting doubt on the words of another or making it very clear to the reader that the author may be of another opinion. You should only use reported speech in formal written language where you are quoting someone else. If you do not use it, the reader will think that what you have written are your own words.