我操
wǒ cào
(substitute for 我肏[wo3 cao4]) fuck
WTF
I (我) + grasp/operate (操) = a raw exclamation of shock or frustration
我操 is a sanitized stand-in for 我肏, a vulgar expletive. The substitution works because 操 sounds similar and shares enough edge to carry the emotional punch, even though its literal meaning is simply 'to grasp' or 'to operate.'
他把我的手机摔坏了，我操，太气了。
tā bǎ wǒ de shǒu jī shuāi huài le， wǒ cào， tài qì le。
he smashed my phone, fuck, i'm so angry.
我操，这道题怎么这么难？
wǒ cào， zhè dào tí zěn me zhè me nán？
wtf, how is this question so hard?