The English language can be very strange indeed. In fact, it's so strange that there are many words which have two meanings (at least) and those meanings are the opposite of each other. How's that for confusing? This phenomenon is so common in English that it even has two words to describe it - auto-antonyms and contronyms. Here are four common contronyms that you've probably used:
1. Cleave
You can either "cleave to" something, or cleave something off. Think of a cleaver - a giant knife you use to cut something apart. If you come across a person discussing cleaving you, pay attention to the preposition they are using - they're either a stalker or a serial killer. Or, for all you optimists, maybe they're perfectly nice and just have an odd way of speaking.
2. Dust
When you dust the furniture you are removing the dirt and grime from it, right? But what if you're a baker and you're dusting a cake with powdered sugar? You're not taking it off, you're putting on a dust-like substance (albeit a much tastier one). Children's book character Amelia Bedelia was once famously thrown off by this contronym when she literally threw dust onto her employer's furniture.
3. Garnish
If you've ever had your wages garnished, you know its not a good thing. Your wages are certainly not being added to, rather money is being taken away from you. To the contrary, if you are garnishing a dish you are adding pretty features to it, perhaps a jaunty kale leaf or an orange peel. However, if your spouse has a dish that looks better than yours you might be excused for garnishing a chunk of that lobster from their plate...
4. Clip
A barber clips your hair, in fact he has a tool named after this action (clippers, naturally). In this sense, clip means to remove hair from you. You can also clip coupons to remove them from the newspaper inserts. But, because English is complicated, you can clip papers to hold them together. You can clip your hair back to make it stay in place, and you can clip a cellphone to your belt to look super cool.
English is strange, and it can be complicated. But it never ceases to be fun to explore - even if you have to pay special attention to context and prepositions to make sure words don't literally mean the opposite of their intended use.