A growing desire by parents to improve their children's English has given a huge boost to sales of English-language books, stores say. The readers are getting younger too, with the latest Harry Potter book widening the series' readership to include younger children. Two bookstore chains said sales of children's English-language books had risen markedly this year. Page One said spring sales had increased by 10 to 15 per cent compared with the same period last year, while Joint Publishing reported a rise of 25 per cent. Emmy Yuen Man-yi, head of the English book section at Joint Publishing's Wan Chai branch, said most customers were parents. 'Parents place a big emphasis on learning English,' she said. 'Perhaps because of our location, a lot of our customers are well-educated professionals and they are more demanding. They want their children to achieve a certain level of English proficiency.' A Page One spokeswoman said: 'Parents now take learning English seriously. We have the impression that they have a great desire to improve their children's English. They put too much emphasis on Putonghua over the past few years.' Ms Yuen said a rise in the number of publishers of English books had also contributed to sales, as prices had fallen 30 per cent compared with four to five years ago. She said more parents seemed to be teaching their children English when they were very young, some even reading to them before they were born. She also said a wider variety had helped generate greater interest. 'In the past you only had titles like X-Men, but now we have Japanese comics but they are just in English, like Initial D. That's another channel to learn English,' she said. Pre-ordering for Harry Potter and the Half-Blood Prince, has been available for more than a month and Page One is reporting strong sales, equal to those for the last Harry Potter book two years ago. But Page One has noted a surge in the number of orders from readers as young as 11 and 12 this year, a trend it believes is partly related to parents' desire to boost their interest in English. The new Harry Potter book will be in stores on July 16.