The document provides instructions and examples for writing a formal complaint letter. It explains that a complaint letter should include an introduction stating the reason for writing, details of the problem or incident, and a conclusion stating what the customer wants the company to do. Tips are given such as using formal language, including a greeting and closing, and rewriting informal sentences into a more formal style. Sample sentences are given and rewritten as examples. Finally, the reader is prompted to write a complaint letter about problems experienced during a hotel reservation.