[dvduval]

Knowledge of 3000 characters in Chinese is enough to read about 99% of text. Many words use two characters. Then there are Chengyu which are generally 4 characters and are derived from an old story. 850 characters would definitely be enough to communicate, and word creation by combining characters together is more flexible than English. Since every character can be a word, it's a little trickier to define what 850 words would mean, as 850 characters gets you thousands more words.