Modern Japanese uses a combination of four different writing systems. The oldest form, Kanji, borrows heavily from classical Chinese. Before the 5th century, Japanese was not a written language. However, after Chinese characters were introduced through trade, the Japanese incorporated this writing system into their language. Initially, the Japanese used Chinese characters to describe Japanese words phonetically. Eventually, Kanji was simplified and evolved into two separate syllabic alphabets. Kanji is still used in Japan to depict nouns, verbs, and adjectives. Although there are thousands of Kanji characters, reading Japanese fluently requires only around 2100 Kanji characters. Contemporary writing also contains elements of the newer writing systems, Katakana and Hiragana.