This week we discuss a kind of error known as an eggcorn. The term was coined by Geoffrey Pullum, who explains. After that, Paul Brians runs down some examples from Common Errors in English Usage.
The Eggcorn Database
Egg corns: folk etymology, malapropism, mondegreen, ???
Far from the Madding Gerund (and other dispatches from Language Log)
Browse other books by Geoffrey Pullum
Some examples from Common Errors in English Usage
“So wrong, it’s right,” by Jan Freeman
“Bu?? naked,” Language Log post by Mark Liberman