The most common spelling/usage mistakes are probably there/their/they’re and your/you’re. Besides these, there’s also to/too/two. I get a particular kick out of misinterpretations like “for all intensive purposes.” I have a good friend who consistently says (I’ll spell it phonetically) “supposevly.” Always good for a chuckle.

As frustrating as these are, none is more annoying than using “loose” in place of “lose.” For example: “If I don’t get some help for my addiction to xbox, I’m probably going to loose my house.” It’s widely done, and not ridiculed nearly enough.

Next time I see this I might just loose it.