china has eight regional languages that are mutually unintelligible, and many true dialects. the system appears to work mainly because as many as 70% speak mandarin. fluency in chinese reading and writing is undoubtedly difficult to achieve, and this must act as a brake on the drive for literacy. there have been a number of attempts to reform or simplify the system. the most radical in pinyin, which is a program to replace chinese characters with an alphabetic system. this was supported by mao, but faltered after his death.