This series contains 10 books for 5 levels. The first level teaching materials aspire to inculcate logical partitioning of sounds, form and meanings, as well as the classification in the degree of difficulty for grammar and usage. The second level teaching materials strive to effectuate natural spoken language in grammar, vocabulary and word use, in addition to speech proficiency for communication. The third level teaching materials attempt the gradual transition from spoken lauguage to written language (using the Empty Triangle to mark informal style and the Black Star for formal styles). The fourth year"s teaching materials continue from the third level, strengthening the development of students"intuition for written Chinese and training them in their capacity to distinguish between formal and informal styles. The fifth level teaching materials center upon written language words, monosyllabic words used within a disyllabic template, commonly used classical patterns.