tortuous/torturous

They differ by only one letter, but their meanings couldn't be more different.

Can you have a "tortuous" job or a "tortuous" workout? Not unless either involves a lot of twists and turns -- and not metaphorical ones.

"Tortuous" refers to things that are full of turns or crooked. You can drive a tortuous road or draw a tortuous line. You can, I suppose, even build a tortuous house, especially if you're not very handy with a level.

"Torturous," on the other hand, is the adjective form of "torture," which refers to pain-inducing. That means your job and your workout are torturous.

Next time you take a ride on a tortuous mountain road, make sure it isn't too torturous.

I don't think I've ever written these two words so often in such a short space -- ever. I hope I don't have to do it again.