So, who cares about grammar and correct word choice? Surprisingly, many people. Writing is often your introduction – to a college admissions officer, potential employer, or future partner. Using vocabulary incorrectly, misspelling words, or forgetting an apostrophe can give the impression that you have limited education and/or intelligence (sorry, but it’s true!).

Even if you consider yourself a good writer, check out these common grammar mistakes (from Inc Magazine’s Christina DesMarais, “43 Embarrassing Grammar Mistakes Even Smart People Make”).  Learn these 37 most common (even among great writers) mistakes so you can communicate clearly and prevent an embarrassing faux pas.

1. First-come, first-serve
   It should actually be “served.” Without the d, the phrase above suggests that the first individual who arrives will be the one who serves everyone, which is not the idiom’s intent.
2. I could care less
   Think about this one for a minute. The way it’s written above suggests you possess care which still could be allocated to the situation in question. “I couldn’t care less” is correct because it communicates that “I have no more care to give.”
3. Irregardless
   This is not a word. It’s simply “regardless,” as in “Regardless of what you think about grammar, you’ll look silly if you use it incorrectly.”
4. “I” as the last word in a sentence.
   This mistake is remarkably common, yet a correct example would be “Karlee talked with Brandon and me.” The trick to getting this one straight is to take the other person’s name out of the sentence and see if your personal pronoun choice still sounds right. “Karlee talked with I” is awkward and incorrect.
5. “Me” as the first word in a sentence.
   I hear people saying things such as “Me and Brandon met at Starbucks this morning” all the
   time, even though it’s always wrong. “Brandon and I met at Starbucks this morning” is correct.
6. Shoe-in
   “Shoo-in” is what you really want to write when you’re trying to say that someone is a sure winner. It’s because when you “shoo” something you’re urging it in a certain direction.
7. Emigrated to
   Emigrate” and “from” always go together, as do “immigrate” and “to.” To emigrate is to come from somewhere, and to immigrate is to go to somewhere. “Colin emigrated from Ireland to the United States” means the same as “Colin immigrated to the United States from Ireland.”
8. Overuse of apostrophes
   These little guys are ubiquitously misused. Apostrophes indicate one of two things: possession or letters missing, as in “Sara’s iPad” and “it’s” for “it is” (second i missing). They don’t belong on plurals. “FAQs,” for example, should not have an apostrophe. Also, people often make a mistake with their own last name. If you want to refer to your family but don’t want to list everyone’s first name write “The Johnsons” not “The Johnson’s.” Another big one: Decades should not have apostrophes. For example, “1980s” is correct but “1980’s” is not.
9. Prostrate cancer
   This one is a simple spelling mistake resulting from an extra r. “Prostrate” actually means to lie face down. The “prostate” gland is a part of the male reproductive anatomy.
10. Slight of hand
    A “slight” is an insult, whereas “sleight” indicates dexterity or cunning. It’s why “sleight of hand” is commonly used in the world of magic and illusion.
11. Honed in
    Just know that to “home in” on something means to move toward a goal, such as “The missile homed in on its target.” To “hone” is to sharpen.
12. Baited breath
    When I think about bait, worms and lures come to mind. The first word should actually be “bated,” which stems from the verb “abate,” meaning to stop or lessen. So, if you’re trying to say that someone is holding his breath, you can see that “bated breath” makes the most sense.
13. Piece of mind
    If you want to share what you’re thinking with someone, this could work if you add “my” before “mind.” But if you’re trying to indicate tranquility, then spell it “peace.”
14. Wet your appetite
    “Whet” means to sharpen or stimulate. As such, the latter spelling is more appropriate.
15. Make due
    “Due” means “owed,” and that’s not the intent with this idiom. “Make do” is the proper way to say that you’re going to get along with what you have.
16. Do diligence
    “Due diligence” is the proper business and legal term. It means you will investigate an individual or company before signing a contract.
17. Peaked my interest
    To pique means to arouse, so the correct phrase is “piqued my interest,” meaning that my interest was stimulated. While the incorrect way it’s written in the heading may suggest that someone’s interest was taken to a high level, it’s still wrong.
18. Must of, should of, would of, and could of
    All those ofs should be “have.” The proper versions were corrupted by contractions such as “must’ve.”
19. ll the sudden
    Whether you say “all of a sudden” or “all of the sudden,” the preposition “of” must be involved either way. But if you’re really trying to say “suddenly,” just do.
20. All the sudden
    Whether you say “all of a sudden” or “all of the sudden,” the preposition “of” must be involved either way. But if you’re really trying to say “suddenly,” just do.
21. Worse comes to worse
    “Worse comes to worst,”–note the t–is better because it indicates something has degraded from one negative plane to the lowest possible.
22. Unthaw
    Even though people use this word as a verb all the time, the best way to “un-thaw” something would be to put it in the freezer. Is freezing what you mean, or thawing?
23. Hot water heater
    If anything, it’s a cold water heater. Just use “water heater.”
24. Boldface lie
    “Bald-face” means shameless or showing no guilt. When a person tells a bald-faced lie, they are openly lying. An acceptable variant of this phrase is a “barefaced lie.”
25. Chock it up
    The correct version–“chalk it up”– comes from keeping score on a chalkboard.
26. Through the ringer
    The incorrect example above is missing a w. A wringer is an old-fashioned mechanism which presses water out of clothes being washed by hand, a process indicative of giving someone a hard time.
27. Subject and pronoun disagreement.
    This one is subject to debate, but here’s my two cents. Take the sentence, “A person who smokes damages their lungs.” See anything wrong there? You should. “A person” is–obviously–one person. But “their” is a word you would use if you were referring to more than one person. Correct sentences could either read:
    1. “People who smoke damage their lungs.”

Or

“A person who smokes damages his or her lungs.”

In the first bullet, “people” is more than one person and now agrees with “their.” In the second bullet, the use of “his or her” can be awkward, so you can just pick one or the
other as long as you’re sensitive to any gender issues an audience might raise.

28. Given free reign
    It’s easy to see why this one looks correct, considering that “reign” is something that kings, queens, and other sovereigns do. Yet the correct idiom refers to the reins which control a horse. When you give a horse “free rein” you let it go where it wants to go.
29. Nip it in the butt
    To “nip” means to pinch or to bite. Therefore, the correct version is “nip it in the bud,” which refers to snipping off a flower bud before it can bloom. The idea is to put an end to something before it gets worse.
30. Tie me over
    You don’t really want someone to tie you on top of something, do you? The phrase “tide me over” is talking about sustaining someone through a difficult time and refers to the ocean’s tide, which is capable of moving boats to a new location when the wind will not.
31. Tow the line
    To “toe the line” means to follow the rules. It comes from runners who put their toe to the line before running a race.
32. Chalk full
    The word “chock” is an Old English word which means “cheek” as well as “full to the brim.” In other words, “chock-full” means “mouthful.”
33. A mute point
    Mute means silent, so would you really want to make a point that doesn’t say anything? A point that is “moot” is debatable or doubtful. So, a point can be moot, but not mute.
34. Expresso
    The strong coffee drink brewed into a tiny cup is pronounced with an “s” in the first syllable and written “espresso.”
35. Eccetera
    Pronounce “etcetera” exactly how it is spelled. Lots of people bristle when a speaker drops the “t.”
36. Deep-seeded
    The incorrect spelling above seems like it could be right since something that is planted deeply in the ground would be firmly established. The correct expression, though, is “deep-seated.”
37. Sneak peak
    A “peak” is the top of a mountain. The correct word is “peek,” which means a quick look.

For the complete list of tips, read the Inc. article.