Stand back, everybody. I’m about to go into Usage Nazi Mode. Most of us, I hope, understand the difference between its and it’s, your and you’re, and their, there and they’re, but here are a few other words that seem to trip a lot of people up.
Rain is water that falls from the sky.
Reign is what monarchs do.
A rein is one of the straps a horse wears on its head and neck, which you can use to give the horse instructions.
Thus, to “rein in” somebody is to exercise greater control over them, as if using the reins to control a horse. Likewise, if you give somebody “free rein” you aren’t making any effort to control them. Except in cases of bloodbending or demonic possession, nobody gets to “reign in” anybody.
Foul is usually an adjective. It means vile, filthy or disgusting. As a noun, it can refer to a violation of the rules of a sport, or a foul ball, a failed attempt at a base hit in baseball.
Fowl means a bird or birds. It is most often used to refer to domesticated birds or game birds, but it can be any kind of bird.
Thus, “fouling” is contaminating or making hazardous, like powder residue in the barrel of a firearm. “Fowling” is the hunting of wild birds. So before you go fowling, be sure to clean the fouling out of your fowling piece.
“Foul language” is profanity. “Fowl language” is chicken or duck noises, or bird calls. “Foul weather” is any sort of weather, such as heavy rain, wet snow or hail, which is extremely unpleasant to walk or drive in. If the passenger pigeon still existed, then an example of “fowl weather” would be a rain of their droppings on the land as their giant flocks darkened the sky… which would actually be a lot fouler than most “foul weather.”
A hoard is a very large pile of gold being sat on by a dragon. It can also be any large collection of something valuable that is being kept hidden from the world.
A horde is a very large group of disreputable-looking people who probably found out about your hoard and are coming to plunder it.
If you are callused, then the skin on certain parts of your body (most likely your hands and feet, but we won’t speculate) has developed calluses — that is, it has become thick and insensitive in patches because of heavy use.
If you are callous, then you are thick and insensitive and don’t care about all those hardworking people getting calluses on their hands and feet and wherever.
When you wait with bated breath, your breath has abated — that is, you're expecting something major to happen any second, and you're holding your breath until it does. Obviously this is uncomfortable for you.
When you wait with baited breath, it's more uncomfortable for the people around you, because you've apparently eaten something that makes your breath smell like bait.
P.S. A rogue will wear rouge if he or she feels like it. Viscous blood is shed in vicious fighting. It would be grisly if a grizzly bear ripped out your gristly bits, but if the bear just started whaling on you, you would still be able to do some wailing. And if your interest in mountain peaks is piqued, take a sneak peek at them. I hope this clears up any further confusion.