I would say it depends on two things, where you are and how old is the person you are trying to communicate with.  While many will not bother, my experience has been totally the opposite.  Maybe I am luckier, but in my case, younger persons do know some English, older persons do not.

Here in China, students are exposed to English lessons since a very early age.  All trhu Grammar School, Middle School and High School they must take English lessons.  Of course some will be more proficient, others really do not care.  But in my shopping trips and travels to nearby places, I always managed to find people that understoodsome level of English.  In fact, while in public buses and or in supermarkets, many times I am approached by locals who wish to pracice their English skills.  I try hard to be nice to all, and compliment them for their efforts, and have made a few very nice friendships out of it. 

I studied French all throughout school but I never actually practiced, so I still can't speak it.  Hell, if I try to make a sentence in French anymore, half of it comes out in Chinese and a couple of words that are Spanish.  Studying just enough to pass whatever test your supposed to pass and memorize stuff just long enough to pass said tests, it's understandable that though some spend years studying in school, they still don't have the skill to actually use it.

Mix that with how it saves face and effort to just say you can't speak instead of trying and messing up.

And that doesn't even count those that have English skills but no experience with various accents, so they get cofused.  

People aren't birds with no brains. They might not be as good as the next person sitting besides you, but they can learn up to a certain amount of words. The human brain can retain a certain amount of knowledge so saying that somebody knows no English is far fetched. At least they can say Hi and bye and at the most they can create a couple of sentences.

Meh. The Chinglish they teach in school is often so bad that I can't even understand what the textbooks my students learn from are trying to say. They spend a lot of time studying English, but learning nothing but garbled dislogic, except in a nicer school where they might have one foreign teacher class for every five Chinglish classes. Expect them to know "hello goodbye 1 2 3 4 5 fuck you" and not much else.

Writing stuff down might help. If they are educated their reading and writing should be at a sufficient level.

It would be better if your friends could speak a little Chinese. Remember you're here and not at home. My Chinese is terrible, as terrible as Chinese English but I can communicate effectively. You can not expect them to communicate in English, you can only hope that they can speak some English to help you along the way.

don't expect Chinese would speak english as well as Europe countrys like german or  Netherlands.  the commoner don't need to speak with foreigner at all. could you image a small company accounting could speak fluent English with you? and most of students in china learning english only for test not for real communication.