regardless/irregardless

This one is fairly common, fairly obvious, and fairly irritating.

The word "regardless" is used to mean "without regard or concern" as in the statement, "Regardless of whether or not it rains, we're going anyway."

Adding the prefix ir- changes the word to essentially mean "not without regard." What you've effectively done is created a double negative, circular logic, and I'm fairly certain a few other laws of grammar, far too complex for the purposes of this blog. Just don't do it!

The bottom line is that the word "regardless" is the standard form and the one to be used. "Irregardless" is not considered standard and should be avoided at all cost. That means it should never be used. Never. You people never cease to amaze me.