Growing up, my grandpa would always correct my dad's grammar. He recognized the importance of speaking and writing clearly and correctly and wanted to pass that along to his son. As a result, my dad did the same thing to me. I constantly heard things like, "you mean 'Mom and me,'" or "you played well, not good." For better or for worse, I often pick up on small errors that people make in speech or writing, thanks to him. Here are some mistakes that keep me up at night that really shouldn't be that hard to fix:
1. Could vs. Couldn't Care Less
I'm convinced that more people say this phrase incorrectly than correctly. If you stop and think about it for a second, it's obvious which is the right way to say it. If you could care less about something, that means you care about it at least a little bit. If you couldn't care less, you literally do not care at all. I could definitely care less about people messing this up.
2. Breath vs. Breathe
I won't spend too much time on this one. Breathe is the verb, and breath is the noun. You can't take a breathe, and fish can't breath underwater. Easy fix.
3. Who's vs. Whose
This is probably the most common mistake I've seen people make, and it's also my least favorite. I've seen countless people on social media say, "who's mans is this?" That phrase in general sounds really dumb to me, but I'll focus on the first word. "Who's" is a contraction of "who is." Would you ever ask, "who is car is parked outside my house?" I hope not. "Whose" is possessive. If you're asking whom something belongs to, use that one.
4. General Words/Phrases That People Mess Up Or Don't Actually Exist
Finally, here are some words and phrases that people get wrong all the time or that have just been made up along the way: First, the word "nother." It looks odd written out like that—that's because it's not a real word. People use it in the phrase, "a whole nother," as in, "there's no way I can sit through a whole nother class today. I have to get to BTC." It's not a word. You probably mean, "another whole class." Another common mistake is when people substitute, "for all intents and purposes," (correct) with, "for all intensive purposes," (incorrect). No matter how intensive your purposes may be, that's not how the phrase goes. Finally, people tend to say they don't feel well when they're sick. In this context, "well" is an adverb. If you don't feel well, that means your nerves don't work properly, and you can't tell when you're touching something with your hands. If you're under the weather, you don't feel good, which is an adjective.
Most people don't care about grammar that much, which is fine. But if you're in an interview or writing a cover letter, it's probably best to proofread and avoid making dumb, preventable errors.