Chinese levels

People have all varying levels of Chinese in my class. Lots of Japanese and Koreans who can write (not sure why Koreans can write, but a lot of them can... i guess they have a pictorial script too... ) but not really understand or speak and who are all mostly very studious. Two Germans with different levels, his is probably better cos he has a Chinese gf, but then maybe not cos all he's learning seems to be sex type words from her. And then there are two Malay-Chinese girls, one who is actually Malaysian and one Aussie. The Aussie has a really good accent but I don't think she knows that much Chinese (just good at pronunciation) and the other sounds kind of Cantonese when she's speaking (she speaks Fujianhua I think?) but can understand a lot, and can't really read or write. And there's me. I can read a lot more than before, and writing I've learnt some just from weekly mini tests on characters I've been studying for. And my listening is good for this level (definitely way above it), but not as good as the Malaysian girls, being used to Shanghainese makes Mandarin tricky sometimes. My speaking is sometimes ok and sometimes way off when I'm having a good or bad day. Some days my tones are so mixed up that I even confuse myself. Speaking to my grandparents every day doesn't help either. They're so deaf and I have to yell loudly to get my point across, it's easier to stick to Shanghainese which I can sustain at a loud level. Mandarin just goes haywire!