The Issue: Auto-Correction Not Learning
I was pulling my hair out. Every time I typed “im” the iPhone would auto-correct it to “IM”, rather than “I’m” which is what I meant.
Normally, if you tap the “x” popup on an auto-correction a few times the iPhone learns that that’s not what you meant. The same thing happens if you go back and fix the word manually. But I must have corrected this particular substitution 100 times and it always popped up wrong.
The Fix: Check Your Contacts
I finally figured out that the problem was in my contacts. No, not my corrective lenses; the issue was with my address book, of all things.
The iPhone OS always adds first and last names and job titles to the auto-correction dictionary. And these can’t be removed by tapping or manually correcting errors. See the problem here?
Some time in the past, I added an SMS bridge to my Yahoo Messenger account to my phone book. This synced to the iPhone with the first name “Yahoo” and last name “IM”. So every time I typed “im”, the iPhone OS looked at my contacts list and decided I was trying to type Mr. Yahoo’s last name. I changed this to “Messenger” and it’s all better now. I suppose I should just delete it, actually…
So there you have it. If you’re dogged by weird auto-correction issues, check your contacts list!