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Indirect speech reports what someone has said. Therefore, it often starts with "He said," "She said," "John said," etc. For example, using #1, above, you might say, "My teacher said that I work hard in school, but should spend more time on homework."
While I am not aware of reference essays that specifically use indirect speech heavily, I think if you keep in mind what indirect speech is, you can construct an essay using it. In your essay you will be describing what someone else has said, so when choosing your topic, pick one which will allow you to refer to what someone has said about the particular subject matter. For example, you could write about what a friend thought of a particular movie: "He said that he liked the action sequences best. He described them as fast-paced and exciting. He called the dialogue somewhat juvenile."
I hope this helps get you started!
Thanks,
Sarah, EssayForum.com
Sarah, EssayForum.com