Sometimes autocorrect can become more of a nuisance than a help. It's annoying to type a word out and have autocorrect completely change the meaning. Sure, some of those words may be slang or not exactly the kind of words we'd text to Mom, but still. It's annoying that the iPhone may turn a word like (insert expletive here) into "duck."
How do you fix that? Simple:
Settings > General > Keyboard > Auto-Correction > Off
There you go. Now you will no longer call someone "a piece of shut."