[Autocorrect] Is it possible to unteach your phone?

iPhone's can be baffling. As the iOS updates have come I swear the autocorrect systems have gotten steadily worse and worse. I know the software is designed to learn your typing so it picks up on words and tries to anticipate certain words or phrases you use (or at least it SEEMS that way), but sometimes it seems the dang thing will "learn" words that are misspelled and constantly try to autocorrect to them.

An example is the word "office". With the 'X' right next to the 'C' on the keyboard, I will semi-regularly type "offixe". Somewhere along the way my phone now thinks that is the word I want to type, so even if I type the word correctly it tries to change it to offixe. I type pretty fast on my phone so sometimes the autocorrect suggestion pops up and I've moved on before I even register what it is suggesting, which means it automatically puts the correction in for me. So I have to backtrack and fix.

Is there a way to tell me phone to forget about the word "offixe"? It would really help if there was a way to customize its vocabulary for the purposes of autocorrect.