Look in General
Go to Keyboard
Tap "Add a new Shortcut"
Use the word you want it to correct to in "Phrase", and use the word that will be changed in "Shortcut".
Note: Leaving "Shortcut" blank will make any words or letters that aren't a real word and are close to the word in "Phrase" will auto-correct to the word in "Phrase".
- 1.0 iPhone 4/4s