Depends on your input mate. If your Chinese blows and they can speak English they will switch to English to facilitate communication. But even in Beijing you can just speak Chinese as long as it's good enough. The bigger the city the less people will put up with bad Chinese. But apart from Beijing and Shanghai any city will do in terms of finding a majority who don't speak English. And it all friends on your Chinese level versus their English level. Whichever is best is the language you communicate in. So as long as you improve everyone will speak Chinese with you unless they're eager to practice their English.

There is no definite answer.People here don't speak much English unless in some foreign companies.

Can you write that in English Ellen? I can't read yet.

中国人的英语基本上都不好 呵呵 放心吧..在北京能找出几个流利说英语的人都难。

Stay away from big cities like Beijing, Shanghai, Guangzhou, Shenzhen etc. Stay away from any cities centers. If you live in a town rather than around the city centre , I think you don't have too much chance to speak English. But people maybe speak in their local dialects in small cities or towns. Good luck:)