Zhuyin (注音 Zhu4 Yin1) literally means "annotate" "syllable" in Mandarin. It is the National Phonetic System for the Chinese language used mainly in Taiwan. The system uses 37 special symbols to represent the Mandarin sounds (21 consonants and 16 vowels). The first four symbols in the system are bo, po, mo, fo, hence Zhuyin is also known as bopomofo to some westerners. These symbols are printed next to the Chinese characters in young children books. One seldom sees these symbols used in adult publications except in dictionary entries.