Rack and Wrack

People! Stop "wracking" your brains! It sounds terribly painful. Actually, so does "racking" your brain. Read on...

Racking something is to stretch it out, as if it were on the medieval torture instrument seen here. You "rack your brain" to try to get information from it. It sounds like a terribly mean thing to do.

Wracking refers to disastrous accidents. Think of it as being similar to "wreck."

He's back...

I've been racking my brain trying to figure out how this lion got into the kitchen. Tonight's dinner has been wracked by his shenanigans.

Reign and Rein

Horses and kings, while having some similarities, are not the same things. Perhaps that is a common misconception that leads to the confusion over the words reign and rein. But I doubt it.

Reign is the period of time a king (or other sovereign leader) occupies the throne (or other way of expressing the seat of power in a government). It can also be used as a verb: to rule, or possess sovereign power or authority.

Rein is that thing that holds horses back.

In The Return of the King, Aragorn does a lot of reining of horses, but takes his sweet time getting around to doing any actual reigning over the kingdom of men.

(Weak example, I know; I just wanted to look at Viggo Mortensen. You're welcome.)