I found the auto correct on my iPhone very annoying and even more annoying when I received a message from my husband that didn't make a lot of sense. (Uhhmmm, honey you really need to put your glasses on....please)
So I turned it off. It's simple, here's how:
Go to Settings,
Then to General
Scroll down and choose Keyboard
Then tap the grey button next to on beside "Auto-Correction".
That's it! Easy hugh?