Hanyu Shuiping Kaoshi (汉语水平考试) Level 4 test (四级), also known as HSK 4, requires mastering a mix of about 600 new Chinese characters and words (字词). These include some of most basic, yet the most frequently used Chinese characters. The challenges for the HSK 4 aspirants would be to recognize these characters in the given contexts. In the HSK Level 4 book series, you will be exposed to all these 600 Chinese characters and words. Each HSK 4 book contains about 30 new Chinese characters from the HSK Level 4 test syllabus. There are about 10-20 examples sentences provided for each of the HSK 4 characters and words. The sentences are explained with simplified Chinese characters, pinyin, and English. Each of the books comes with five short essays (短文) and stories (故事) based on the characters and words introduced in the book.