* What is it?
Malapropism, is the use of an incorrect word in place of a word with a similar sound. It is a form of wordplay.
* Why is it used?
Malapropism, can be used for a few reasons.
One reason is just because it's funny. A character saying a word with confidence, when the audience knows it is the wrong word, can be comical.
Another reason is to show a character's state of mind; stress, confusion, or in Jack Sparrow's case, drunkenness. The character is flustered, knows the word he wants to say, but says the wrong one instead.
A third reason, is use by accident or ignorance. The speaker simply doesn't know he or she is using a word incorrectly. The word they use sounds similar to the one they want to use. They know the definition of the word they want to use, but they don't know the word that matches that definition.
The third example of malapropism is especially hilarious, when used by real life politicians!
Got any favorite examples of malapropism?