Every day, you type in dozens of messages on your mobile phone, and most of the time, you do it wrong—you mistype, misspell, or make some other kind of error that will make you embarrass. Most of the time, your phone steps in to save the day. Thanks to the genius of autocorrect, you can feel free to type "thw" or "unviersity" without embarrassment.

So how does autocorrect works? The basic algorithm behind autocorrect is pretty simple. The system is essentially the same as a word processor's spell checker—as you type, the system checks each word against a built-in dictionary, and it suggests alternatives when it doesn't find a match. Many phones will also try to predict what you're going for and suggest a word before you've finished typing it.

A correct dictionary and an accurate "language model" that determines which words to suggest are the essential part of autocorrect. To build a dictionary suitable for users would be to collect and analyze a large sample of words that people actually type in to their devices. The dictionary will pay attention to when you recorrect a corrected word, and learn never to offer that faulty choice again. For example, it will also note the proper nouns in your address book and avoid suggesting alternatives for those.

         Here is a quote from the internet about how to transform a word that you put in.

         So we can tell that there are so many possibilities of transformation for a word. It is easy for autocorrect to make the wrong suggestion. And actually during my research I have found a lot of funny autocorrect fails in the internet. But we shouldn't expect too much from the autocorrect because we are actually the source of its dictionary. The computer just did the memorizing and parsing to find out the most often used suggestion for us. The system isn't going to be perfect but it is really useful. 

(A Funny autocorrect fail)

Photo Reference:

1.http://www.iphonelife.com/blog/31961/tip-day-how-teach-ios-autocorrect-new-words

2.www.damnyouautocorrect.com/

Writing Reference:

1.https://www.quora.com/How-are-typing-auto-correct-or-suggest-algorithms-implemented

2.http://smallbusiness.chron.com/googles-autocorrect-work-59730.html