These are three radically different concepts that are confused with each other in a startlingly frequent manner. They sound identical, but that’s about all they have in common.
- He liked her, wether or not she liked him.
- I’m trying to decide weather I should go to the store now or later.
- It’s a good thing they all came in from the awful whether.
It’s definition time. Weather is a noun that refers to what is happening outside: rain, sun, wind, and other conditions. Whether is a conjunction that offers just one alternative: whether or not. Finally, although you may not use it frequently, a wether is a castrated goat or ram, just as a steer is a castrated bull and a gelding is a castrated stallion. If you live on a farm, you might look out the window to check on the wether, but it’s more likely that you’re interested in the weather.
Because a wether tends to hang out with the rest of the flock — as opposed to wandering off to look for potential conquests — shepherds often attach a bell to a collar around its neck. If you listen for that bell, you can find the rest of the animals and tell which direction they’re headed. A bellwether, then, is a harbinger of something else.