Andy,
This is the reason they need native English speaking teachers in China. What your probably learning is the correct spoken and written mandarin, Where as what is commonly spoken is sometimes very different.
When we speak to our friends, we often leave out words, or a bit of slang gets thrown in, that's exactly what happens in Chinese too!! ....Confusing?? You bet it is, which is one reason i gave up trying to learn the language fluently, that and the many different tones to the same word...lol!! But i can still get by quite well with some very, very simple sentences and a vocabulary of about 250 words or so.... lol!!
Just use the correct terminology your being taught for now, at least they will understand what your saying, and leave the slang and abbreviations to a later date when you understand the language a bit better..... if ever!! ...haha!!
David.....