And it's cool that people who speak Cantonese won't understand people who speak Mandarin unless they've learned Mandarin. However, people who speak Taiwanese could kinda understand people who speak Mandarin. Samething for Shanghai. Right?
You are partly correct,but not exactly.
For the illiterate person they might don't know the mandarine.AS I said before,Mandarine is our offical language,so even a person only finished his/her primary school(our school being demanded that the instruction of language is mandarine) he/her will know how to speak Mandarine,however ,it may be not accurate.Ok,so do Taiwanese and Shanghai.
China has 56 nationalities ,each one has his own language,it is hard for us to know the whole.I even dare not to think about it.
