Today the Chinese are obsessed with English. Anything up to a fifth of the population is learning the language. As Gordon Brown, the British finance minister, observed on a trip to China last year, in two decades China’s English speakers will already outnumber native English speakers in the rest of the world. This is fuelling a market that comprises everything from books, teaching materials and tests to teacher training and language schools themselves. At $60 billion a year, China is already the world’s largest market for English-language services, estimates Mari Pearlman at ETS, an American group that developed TOEFL, a well-known test of English-language proficiency.