Killing two birds for the price of one!

[xross_fire]

What are some of the most commonly misused idioms and/or your favorite improper ones?

ie. "without further adieu" which should be either "ado" or "without further saying adieu," and "killing two birds for the price of one" - an improper combination of two

 

[RobertJ]

This isn't really an idiom, but I noticed a lot of people (at least around here) say, "I could care less". Really what they mean is "I couldn't care less."
I don't bother to correct this.

 

[Artifice Orisit]

Really what they mean is "I couldn't care less."

Or they're retentive about technical accuracy.

(I prefer not to say "Anal")