Vain people love mirrors. A vein, though, moves blood through your body. And a vane is a big metal rooster on a rooftop showing which way the wind blows.

To be vain is to be conceited, stuck up, and full of yourself. The other meaning of vain is to do something unsuccessfully. If you look for your phone but don't find it, your search was in vain. Here are some examples:

Omi wasn't vain or stuck-up or anything like that, but she really cared how she looked. (Maybe He Just Likes You)

His bowler hat is already dry as he attempts in vain to cover both of them with the open umbrella. (The Night Circus)

A vein, on the other hand, carries blood to your heart. Streaky lines, like in marbles or blue cheese, can be called veins, too. You can also say that similar things are "in the same vein." On that note, here are some examples:

If something had happened — I ripped off the covers, my blood like ice water in my veins. (The Sea of Monsters)

Zooming past the white water and onto the vein of ore, they sighted the ruins just as the sky was beginning to change. (Uglies)

Last but not least, vane is short for weathervane. It's a flat or curved surface, connected to an axis, that spins in the wind. These examples show us which way the wind blows:

My mind spun like a weather vane in the wind. (Worth)

"It’s a weather vane so it shows us which way the wind is blowing," Alonzo said, adding that it "reminds us that things can change very quickly." (New York Times)

Don't let reading this be in vain — keep these words separate by remembering that a vein is in your body, and a vane can indicate north or east.