Some examples for indirect speech
Indirect speech is often called reported speech. This definition pretty much explains the meaning of the term: someone said something and the narrator reports it. For instance, a guy said, “I’d like to have an ice-cream”. What you do is report to others what that person just said without actually repeating every word, but by conveying the very sense of the statement. “He said he would like an ice-cream”. It is good to remember that reported speech or indirect discourse often requires sticking to the sequence of tenses.
Basically, the verbs in present simple are changes to those in the past simple; past simple and present perfect are replaced with past perfect, etc. But in some cases, the natural sequence of tenses is used. This often goes when the statement is equally relevant now. For instance: “We live in the Solar system” – “He said we live in the Solar system”.
The writer, according to Wikipedia, has to use the verb that he would have used in the situation determined by the main verb. In daily speech, we rarely use complex structures, tending to simplify the speech. The natural sequence may also be a better variant for copywriters and other professionals who deal with writing in purpose of mass communication.