Character amnesia
It is difficult to establish exactly how many different Chinese characters are in use today; the new HSK, a widely used proficiency test for Standard Chinese as a second language, tests over 2,600 different characters, whilst in 1988 the People's Republic of China published the "List of Commonly Used Characters in Modern Chinese" which contains 7,000 different characters. In Japan, where a smaller set of characters are in general usage, the Japanese Ministry of Education prescribes the teaching of 2,136 kanji in primary and secondary school in a list called the jōyō kanji, meaning "regular-use Chinese characters".
Chinese characters
When the script was first used in the late 2nd millennium BC, words of Old Chinese were generally monosyllabic, and each character denoted a single word.
Increasing numbers of polysyllabic words have entered the language from the Western Zhou period to the present day.
It is estimated that about 25–30% of the vocabulary of classic texts from the Warring States period was polysyllabic, though these words were used far less commonly than monosyllables, which accounted for 80–90% of occurrences in these texts.
The process has accelerated over the centuries as phonetic change has increased the number of homophones.
It has been estimated that over two thirds of the 3,000 most common words in modern Standard Chinese are polysyllables, the vast majority of those being disyllables.