This book is designed specially for users who study Mandarin Chinese with the Pimsleur audio program. It is not a textbook for the program but a collection of information that might come in handy for Pimsleur students, like a systematic grammar overview (which the audio program does not provide).
Another goal is to provide some access to written Chinese (simplified Chinese) resp. to the Pinyin system. Since most Chinese are not really familiar with the Pinyin romanization, it cannot be used in written communication. Still, even for students who decide not to spend time to study the Chinese writing, it is highly recommendable to acquire knowledge of the Pinyin writing. At some point, every student needs to go beyond the vocabulary and the grammar that the Pimsleur program provides, and look up information in a dictionary or textbook. Without knowledge of at least the Pinyin writing, this is hardly possible.