iOS: There are a few ways you can fix the iPhone's helpful, but sometimes annoying, autocorrect feature. Unsurprisingly Apple's software ebbs towards somewhat puritanical word choices -- like "duck" when you meant something else. The quickest and dirtiest way to sneak your swearing into autocorrect's vocabulary is to add a contact with the words you want it to learn. On Twitter, Steven Thrasher suggests you add a contact named "Fuck Fucker", and perhaps "Fucked Fucking", or whatever verbiage frequently causes autocorrect to have a fit.
Best life hack ever: add "fuck fucker" & "fucked fucking" to your iPhone contacts & never mess with correcting "duck" "ducked" etc again pic.twitter.com/YhZAp6vDKf
— Steven Thrasher (@thrasherxy) October 7, 2016
You can also just add words to the iPhone's dictionary, if you want to go the proper route. In the keyboard settings, look for Text Replacement. That's designed to create text replacement shortcuts -- typing "omw" to write "on my way", for example -- but you can also just add full words like "fuck" or "shit". Either way, teaching autocorrect proper diction only takes a few extra steps.