Every term, I repeatedly beg my ESL students to turn off the spellchecker on their computers, as it tends to lead to some awful errors. Sure, some of them are pretty funny as well, but that's not the point.
The first problem comes when a student mistypes a word and the spellchecker pops in with a couple of possibilities. The student often will just pick one -- without looking to see what it really means, presumably thinking that the first one must be right. The second is that if the spellchecker doesn't find any errors, the student believes there aren't any and doesn't proofread the paper, forgetting (even when his teacher has talked about it ad nauseam) that the spellchecker won't help if one is using the wrong word spelled correctly.
These two situations lead to errors such as the following (all from real student papers):
"In the winter you should wear worm clothes." (Sounds kind of slimy and uncomfortable)
"She did it with her bear hands." (A serious need for a manicure if I ever heard one!)
"Columbus mare needs ... to reduce crime rate." (Yes, she was referring to His Honor the mayor.)
"The U.S. is the single supper power in the world today."
"The U.S. has become a save heaven for so many people from different part of the world."
I am going to need to come up with some exercises for students to proofread just for spelling. I think I'll start with the above sentences and work from there. Any suggestions would be much appreciated!