I'm currently jotting down every bit of highly used vocabulary and grammar, its almost essential for me to learn similar words and phrases at the same time so that they aren't confused later. Here is an example that I was mixing up before and was able to piece together yesterday.
zěn me
what?, how?, why?
zěn me le
whats up? whats going on?
zěn me yàng
how about (something) how was it? how are things?
zěn me cái
why are you late ( in doing something)
example: nǐ zěn me cái lái (literal translation: why are you late coming? or arriving)
zěn me can be used in many other ways, just type it in the box at the top left corner (MDBG search box) and see for your self. If anyone has something useful to add don't hesitate.
Like most of you in China I'm studying Mandarin and doubling as a teacher, when you learn how to teach a language you learn the proper way to learn a language. So for anyone not teaching, here is something to absorb:
http://esl.about.com/cs/teachingtechnique/a/a_teachgrammar.htm
