Kelsey, please check the WWOOFer FAQ for helpful tips on how to get hosts to respond. As Joep de Wit writes above, using every available means to communicate will yield more options for you. We suggest you telephone the hosts first, then text and email. if you email, include a brief greeting in Chinese.
Most of our hosts are farms and if you have encountered one that has no farm, please let us know through our contact form the host number so we can investigate. It is true that many of the farms are also very interested in learning more English language.
Many hosts do not have internet (some do) and use their telephones for email and internet. Also, while many hosts understand some English, they may not be able to read it. Each host is different. We have some that have WiFi and others with very little connectivity.
I hope this helps you to find the hosts you are seeking in the geographic region you want to travel in.