Accidentally Saying Chinese Swear Words
A story tells of an ethnic minority student who simply wanted to borrow a pen from a female comrade. Ethnic minorites in China are often as tone deaf as Westerners, and when the guy wanted to borrow a pen (借你的笔 / jie4 ni3 de bi3), it became 借你的屄 (jie4 ni3 de bi1), and the female student got all red in her face pondering the proposal of lending her cunt to that fellow...

The words and tones to look out for are the following:


cào (肏，操), which means fuck (often heard as 我操, i fuck, simply meaning fuck)
bī (屄，逼), which means cunt (often rendered as 傻屄 or 傻逼 (sha3bi1), meaning stupid cunt)


gàn is not problematic in China, only in Taiwan.

mā de (妈的) is a very mild swear sentence in China.