I've noticed a lot of people making little mistakes when writing English and these mistakes seem to have caught on and occur regularly. A couple of examples of this that I seem to see most often are :
1) writing the word 'brought' where the word 'bought' should be used and
2) writing the word 'quite' when 'quiet' should be used or vice versa.
I don't know if its maybe just regional accents playing a part in affecting the way that people write these words. Maybe people from certain areas of the country are writing in their own regional accents or maybe its just nowadays on forums, chat rooms, facebook and messenger its become the norm to write in an informal way. The strange thing about our language is that making these tiny mistakes such as shuffling a couple of letters around or throwing in a random 'r' can completely change the context of the sentence entirely.