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99 most common grammar mistakes

Does proper grammar seem daunting to you? Not sure if you should use the word âirregardlessâ or âregardlessâ in a sentence? Or how to use an infinitive verb?
The English language is finicky enough that a single missing comma can radically change the meaning of, well, everything you were trying to say:
Letâs eat friends! is more than a little creepy, while
Letâs eat, friends! sounds warm and inviting.
Itâs our hope that this guide helps you avoid such blunders.
99 most common grammar mistakes in writing
One of the questions our subscribers ask most, whether theyâre proofreading pros or full-time students, is how they can avoid the most common grammar mistakes. In this list, we outline some of the most common grammatical errors weâre seeing, based on millions of data points from Writer subscribers.
1. Letâs vs. Lets
Letâs not get carried away here â this one is pretty simple:
Letâs = let us. As in, let us not get carried away hereâŠ
Lets = to make something possible. This checklist lets you write better.
2. Its vs. Itâs
Itâs simple:
Itâs = it is. As in, itâs so dang cold outside.
Its = associated with something recently mentioned. As in, the weather has a mind of its own.
3. Your vs. Youâre
Your is a possessive pronoun that describes ownership of an item: your jacket is sweet!
Youâre is the contraction of you are: youâre probably glad you have that jacket.
4. May vs. Might
May indicates a possibility; might indicates a hypothetical probability. I may quit my job â even though Iâm good at it.
Then again, I might get fired.
5. Lay vs. Lie
Lay describes the action of placing something flat: lay down, Fido!
Lie describes the status of something resting flat: Fido likes lying (lie-ing) down.
6. Affect vs. Effect
Affect implies action: âI want to affect the world in a positive way,â said Jane. Effect describes its result. âThe effects of your intention should be good,â replied her friend. Find out more about Affect vs. Effect here.
7. Too obvious?
Is this one too obvious, or not? Based on what must be billions of text-message bloopers itâs probably worth mentioning! Too refers to, well, too much of something / too many of something: âI have too much money to live in such a small house.â
It can also be used as a form of agreement: âyeah, I feel that way too.â
8. To vs. two
Two is a number (you know, this one: 2). âToâ is a word meant to be used in all sorts of different ways.
9. There vs. their
There refers to a location; their refers to a designation:
âSee that restaurant over there?â â âYep, thatâs their favorite one!â
10. Their vs. theyâre
Theyâre = they are:
âTheyâre going to love that restaurant!â â âYeah, like I said itâs their fav.â
11. Loose vs. lose
Loose refers to something thatâs been let out of control. While lose-ing is the opposite of winning! âDonât be afraid to let loose. After all, what do you have to lose?â
12. Peek vs. peak
Peek means to look at something; peak refers to the top of something.
âCan I take a peek of the scenery?â â âSure, but I heard the viewâs better from the peakâ
13. Peak vs. pique
We already mentioned what peak means. Just in case you were wondering, though, donât confuse it with pique, which means âto stir upâ â âmy interest was piqued.â
14. Compliment vs. complement
While both of these words refer to nice things, their meanings are quite different. A compliment is something nice you tell someone; complement refers to things that go well together.
Hereâs a brain-bending compliment: âYour shoes complement your outfit so well!â
15. Piece of mind vs. Peace of mind
A piece of mind refers to oneâs perspective or opinion: âMy neighborâs truck is so loud, itâs about time I gave him a piece of my mind!â
Whereas peace of mind refers to a mental framework: âYeahâŠall that noise is really hurting my peace of mind.â
16. Literally
If you use the word literally, be sure to use it, well, literally! Watered-down words are no good for anyone.
17. To comma or not to comma
Commas are tricky little beasts. Sometimes skipping an oxford comma or two (even if using one would be grammatically correct) is actually a good call, so trust your instinct.
âOnce upon a time, there was this really good writerâŠâ
âYeah I heard she didnât always use commas.â
18. Semicolons
Semicolons are actually more like periods than commas. They usher in a new train of thought.
Semicolons are actually more like periods than commas; they usher in a new train of thought.
19. Semicolons + commas
Sometimes, though, semicolons are best followed up by a comma; in cases such as these, itâs totally okay to use them both!
20. Semicolons vs. commas
Many times commas work just fine by themselves, so donât use semicolons if you donât need to.
Many times commas work just fine by themselves; so donât use semicolons if you donât need to. (Doesnât that look awkward?)
21. Parentheses and periods
Normally periods and other punctuation marks go after parentheses (normally).
22. Periods inside parentheses
The exception is if youâre writing an entire sentence within parentheses â like the example in mistake #20 above.
23. Quotation placement
âPeriods, commas, question marks, exclamation points, quotations within quotations, etc. should always be placed inside quotation marks,â he explained.
24. Unless youâre outside the United States
Thatâs right: in most other countries, punctuation marks actually go outside quotations. Go figure.
25. Plural or singular!
It really donât sound good if you doesnât stay consistent with plural and singular formsâŠ
26. Hyphens vs. dashes
A hyphen, like the one to the right, connects two or more inter-related words â a dash, like the one just to the left, connects two or more related thoughts.
27. En dash or Em dash?
An en dash is about the width of the letter âN,â and itâs meant to show a range, like 1-10.
An em dash is longer â itâs meant to facilitate those fun connections we mentioned earlier.
28. Inappropriate hyphens
In general, donât use hyphens to connect two parts of one word. The way we spelled âinter-relatedâ up there? YeahâŠthatâs incorrect. Unless youâre trying to prove a point.
29. Missing dashes
On the other hand, donât rule out the use of hyphens entirely. They can be insanely-awesomely-silly-ly useful!
30. Donât be too negative
Actually, forget that â be positive. After all, why negate a negative when you can present a positive instead?
31. The other kind of double negativeâŠ
Ever feel like you canât do nothing right? Maybe like you canât spell nothing correct at all? Please, donât ever write like this. Unless youâre authoring a Southern-twanged novel or something.
32. Dot-dot-dot
Some people like doing dots like thisâŠ
Others like this method . . .
But feel free to use whatever resonates most with you.
33. Dash spacing
And some people donât like having spaces around their em dashesâthey can get pretty particular about it. Best-selling author Tim Ferris leaves spaces around his, though â so apparently it doesnât matter too much.
34. 50 cent(s)
This is like the mathematical version of the double-negatives we mentioned earlier. If youâre trying to denote a certain number of cents, either write out the full decimal, or list the number of cents:
50 cents, or $0.50
Donât do both: $0.50 cents
âŠunless, of course, you really are talking about half of one centâŠ
35. The issue of marriage
In this case, marriage is only an issue if the term is used incorrectly:
âShe was married with a football player.â
Saying âshe was married to a football playerâ just sounds way better.
36. Each and every student
The term âeveryâ almost always goes with a singular noun:
âEvery student passed the testâ is correct, while âevery students passed the testâ is not.
37. Although/but
The words although and but donât often work well together. Try to use one of them or the other, not both!
Although it was raining, we still went outside.
or
It was raining, but we still went outside.
38. You and I
âPam and me went to get some groceriesâ is incorrect;
âPam and I went to get some groceriesâ is spot on.
39. Amount vs. number
âAmountâ should be used for something uncountable: âa large amount of dirt.â
âNumberâ should be used for things you can quantify: âa large number of people.â
40. Fewer vs. less
âLessâ should be used for something uncountable: âless dirt.â
âFewerâ should be used for things you can quantify: âfewer people.â
41. Shared possessions
If youâre sharing something, then itâs enough to use one apostrophe: This is Tim and Andyâs house.
42. Thatâs all well & goodâŠ
âI slept wellâ is correct; âI slept goodâ makes it sound like you need a little more sleep.
43. Or is it good & well?
If youâre describing the quality of something, however, âgoodâ can be a very good fit.
44. The police is coming!
Actually, the police are coming. Unless this is also part of that slang-infused novel youâre writing.
45. A vs. an
Do you have an idea of whether or not this sentence is grammatically correct? Hint: it is!
46. Amicable/amiable
âAmicableâ should be used to describe pleasant meetings and such; âamiableâ should be used as a synonym for âkind.â
47. Write vs. right
This article is meant to help you writeâŠthe right way.
48. Beside/besides
âWant to sit beside me?â is more correct than âwant to sit besides me?â
49. Farther/further
âWant to bike a little farther?â is more correct than âwant to bike further?â
50. Can vs. may
âCanâ implies an ability; âmayâ implies a possibility.
51. Since/for
Iâve been in Europe for 3 weeks. Iâve been in Europe since the first. If you try swapping âsinceâ and âforâ in the above sentences, it just doesnât work.
52. No one vs. anyone
âHe didnât know nobodyâ is incorrect; âhe didnât know anyoneâ is much better.
53. More smart, or smarter?
If you want to sound smarter, try to avoid talking about being âmore smartâ than others!
54. A lot/alot
Did you know that âalotâ isnât a word? Use âa lotâ instead
55. Alot/Allot
Unless, of course, what youâre really trying to say is âallot,â a word which means âto give or assign.â
56. Wreck vs. wreak
The wreck wreaked havoc on several of the cars involved.
57. Pore vs. pour
A pore is a small opening; a pour is whatâs done to a drink!
58. Ran vs. run
âI ran fastâ and âI run fastâ are both correct, but they do have slightly different meanings. If youâre still pretty quick, use the ârunâ version.
59. Suppose so?
Youâre supposed to use âsupposeâ in the above type of situation.
60. Collocations
Some words just go better together. âDue to the fact thatâ is one prime example. If you use collocations like these, donât try to divide them up!
61. Got know-how?
âI know how to write.â âIâve got business writing know-how.â While both of these sentences are grammatically correct, one is much less awkward than the other.
62. Keep tense consistent!
âI went to the grocery store and buy some eggs.â â See how improper that sounds? Make sure you keep your tense consistent, whether itâs past or present or future tense youâre talking about.
63. Unless youâre talking about something universalâŠ
If youâre talking about a timeless truth, though, you can switch your tense up a little:
ââThe earth revolves around the sun,â his parents explained.â
64. Seniority
âHeâs senior to meâ works, and so does âheâs older than meââŠbut donât try to flip these around: âheâs senior than meâ and âheâs older to meâ are both wrong.
65. Neither/nor
âNeitherâ and ânorâ go great together: âShe was neither stronger nor faster, but she was still a great athlete.â
66. Cardinal vs. ordinal
Cardinal numbers deal in absolutes; this is grammar mistake #66. Ordinal numbers deal with positions; this is the 66th grammar mistake listed.
67. Spell it out
Typically numbers under 10 should be spelled out, though there may be one or two valid exceptions to this rule.
68. Missing articles
Donât forget to put the word âtheâ before appropriate items: the book, the blog, the article, and so on.
69. One should stay consistent
If youâre speaking about another person, use consistent pronouns: âOne should stay consistent when they are writingâ sounds much better than âone should stay consistent when he is writing.â
70. Hard vs. hardly
âWriting is hard.â â Correct
âWriting is hardly hard when you use Writer.â â Also correct!
71. Hardly vs. hardy
âCarrots are very hardly vegetables.â â ??
âCarrots are very hardy vegetables.â â Correct.
72. First come, first served?
Though most people (i.e., restaurants) will say âfirst come, first serve,â what makes much more sense is âfirst come, first served.â
73. Shoulda woulda coulda
âShould of,â âwould of,â and âcould ofâ are actually all incorrect, though they might sound decent enough.
The proper usage, of course, is âshouldâve,â âwouldâve,â and âcouldâve.â
74. Wait, so you could or couldnât care less?
Many people use the phrase I could care lessâ to describe something they donât really care about. If you think about it, though, what theyâre trying to say is that they couldnât care less.
75. âIâ shouldnât come last
âAt the restaurant, it was just her and Iâ just doesnât sound as good as âAt the restaurant, it was just me and her.â
76. But âmeâ shouldnât come first
The above writing mistake also has an inverse:
âMe and her went to the restaurantâ just doesnât sound as good as âHer and I went to the restaurant.â
77. Apostrophe calamity
The Johnsonâs. The 70âs. The JonesâsâŠlife is simpler without all these apostropheâs!
Try the Johnsons, the 70s, and the Jonesâ instead
78. Mmm, expresso
While âexpressoâ might sound correct to some, itâs actually spelled âespresso.â Just FYI.
79. A sleight of hand
Thatâs right: a âslight of handâ is actually incorrect!
80. Forte, niche, and other mispronunciations
Forteâs pronunciation =Â fort.
Nicheâs pronunciation =Â neesh.
Just donât spell either of them that wayâŠ
81. Exact revenge!
If you must have your revenge, donât extract it, exact it!
82. Soggy appetites
âThat really wet my appetite.â â Incorrect
âThat really whet my appetite.â â Correct
83. Do your due diligence
See what we did there? Itâs âdue diligence,â not âdo diligence.â
84. Per say
âPer seâ is a Latin phrase meaning âin itselfââŠper say is how you pronounce it.
85. Worse comes to worst
While weâve all heard the phrase âif worse comes to worse,â it doesnât really make sense unless âworseâ goes all the way to âworst.â
86. Chalk it upâŠ
âŠdonât âchock it up.â
87. Free rein
To give âfree reinâ to something means to let go of control.
To give âfree reignâ implies kingship without effort.
88. Nip it where?
In the bud, not in the butt! For those unfamiliar, this phraseâs literal meaning refers to nipping flowers in the bud.
89. Disinterested vs. uninterested
These two terms arenât actually synonyms. Being disinterested implies that you couldnât care less; being uninterested means you care enough to turn your interest away.
90. Nauseous vs. nauseated
Donât worry: almost everyone gets this one wrong. âNauseousâ technically means to be capable of making others nauseated; ânauseatedâ means not feeling well.
91. The impact of impactful
Is impactful a word? Contrary to what you may have heard, it is â so donât let people tell you otherwise.
92. However vs. nevertheless
Fans of classic grammar will insist that sentences shouldnât be started with âhowever,â at least not when they can be started with âneverthelessâ instead. Weâd say use whichever sounds better to you.
93. Too many sâs
When in doubt, drop the extra s. Arkansasâ is usually preferred over Arkansasâs, for example.
94. Run on sentences
Contrary to popular belief run-on sentences arenât necessarily long they simply occur when commas and/or other types of punctuation are missing like this.
95. Too many commas
Using too many commas, on the other hand, isnât good either, because it can reduce the casual flow, from word to word, that you should strive for.
96. A break from parallel
âHe was studying math, science, and digital photosâ might not sound that bad, but why not say, âhe was studying math, science, and digital photographyâ instead?
97. Sentence splice
I wanted to cook a great dinner, however I was just too tired.
I wanted to cook a great dinner; however, I was just too tired.
I wanted to cook a great dinner. However, I was just too tired.
The first of these three sentences is incorrect. Why? Because itâs spliced together without the appropriate punctuation.
98. Misplaced semicolons
On the other hand; using semicolons where theyâre not needed (say, in place of commas) isnât good either.
99. Incorrect capitalization
You probably know to capitalize proper nouns and the first word of each sentence. But sometimes you also need to capitalize after a semicolon or the first word of a quote.
Christine explained, âCommunity is key to building a successful online business.â
7 major types of grammatical errors
Bad grammar can make a poor first impression, whether youâre writing a business email or messaging a potential date. People tend to make assumptions about your abilities based on how you communicate. If you’ve made it this far and want to learn how to write better, let’s look at some examples of bad grammar.
Verb tense errors
One of the most common grammar mistakes is using the wrong verb tense. The verb tense tells your reader when the action takes place: in the past, present, or future. When writing anything, you want to be consistent on verb tense unless there is a good reason to switch tenses.
The mistake:Â I drive to the store and I bought shoes.
Why itâs wrong: A verb tense shift happens when the writer changes tense in a sentence or paragraph. In this case, drive is present tense and bought is past tense.
The correction: You should change drive to drove, or change bought to buy to make the sentence correct. Be mindful of shifting tenses within a paragraph.
Subject-verb agreement
The subject of the sentence (the person or thing doing the action) and verb (the action) in a sentence must agree with each other. If the subject of the sentence is singular, the verb must be singular. If itâs plural, the verb must be plural also.
The mistake:Â Michael and Sue is going to the beach.
Why itâs wrong:Â âMichael and Sueâ are plural. The auxiliary verb âisâ is singular, which is a lack of agreement.
The correction:Â The sentence should read, âMichael and Sue are going to the beach.â
Comma splice
A common punctuation mistake is the comma splice. A comma splice happens when two separate sentences take place rather than using a period or semicolon.
The mistake:Â I went to Steveâs house, and ate lunch.
Why itâs wrong:Â Writers often use a comma splice when they connect two independent clauses with a comma rather than a comma and a coordinating conjunction.
The correction:Â Use commas to separate two independent clauses when they are joined by coordinating conjunctions: and, but, or, for, so, yet. In the compound sentence above, âand ate lunchâ doesnât have a subject, so you donât need to add a comma before âandâ.
Small punctuation errors like this seem like a small thing, but punctuation helps guide readers through your text smoothly. You can use a punctuation checker to double check your work and correct these grammar errors in minutes.
Misplaced or dangling modifiers
A misplaced modifier is a word, phrase, or clause that is separated from the word it modifies or describes. A dangling modifier is a grammatical error where the modifying word is too far away from the subject of the sentence, or there is no subject.
Sentences with these mistakes often sound awkward or confusing. But donât worry, misplaced and dangling modifiers are common writing mistakes and even trouble the experts in English grammar.
The mistake:Â Disappointed, the story took me forever to write.
Why itâs wrong:Â The modifier should be as close as possible to the thing it modifies. Since the subject of the sentence is disappointed (not the story), the sentence should have the speaker and modifier closer.
The correction:Â The sentence should read, âI was disappointed by how long the story took me to write.â
Overuse of adverbs
An adverb is a word that describes a verbâthey often end in -ly. Writers use adverbs to give more information about the verb and make it more descriptive. Using adverbs every so often isnât bad grammar, but too many can mean poor verb choices.
The mistake:Â The wedding went really bad.
Why itâs wrong:Â The adverb âreally badâ modifies the verb âwentâ. While âreally badâ gets the point across, does it really paint a picture for the reader?
The correction:Â Use a more descriptive sentence like âthe wedding was a disasterâ instead.
Passive voice
English grammar experts and teachers consider passive voice a bad writing habit. With the passive voice, the object of the action becomes the subject of the sentence. Itâs recommended to turn passive constructions into active voice, where the subject does the action of the verb in a sentence. Active voice can make your writing stronger and more direct.
The mistake:Â The car was driven by Chris.
Why itâs wrong:Â The last words in the sentence âby Chrisâ make up a preposition that tells the reader who is performing the action. Even though Chris is performing the action, he is not the subject of the sentence. You could remove him from the sentence entirely using passive voice.
The correction:Â The active voice construction would be âChris drove the carâ.
Sentence errors
Sentence structure mistakes are one of the most common grammatical errors. You can break down sentence errors into three categories: sentence fragments, run-on sentences, and overloaded sentences.
Sentence fragments
Sentence fragments are clauses that miss one of the following elements: a subject, a verb, a complete thought. You often miss fragments because they are no big deal in spoken grammar, aka conversation, but can make a big impact on your writingâs clarity.
The mistake:Â He still loved his parents. Despite everything that had happened.
Why itâs wrong:Â The second sentence âdespite everything that had happenedâ has no subject or verb. You depend on the first sentence to give the second one meaning.
The correction:Â The complete sentence for this clause is âDespite everything that happened, he still loved his parents.â
Run-on sentences
Run-on sentences, also known as fused sentences, happen when two complete sentences are brought together without any punctuation or conjunction, such as a semicolon or period. Run-on sentences donât have to be long to be considered grammatically incorrect.
The mistake:Â Yesterday was the best day ever my family and I began our ski vacation.
Why itâs wrong:Â There is more than one idea communicated by two independent clauses.
The correction:Â Yesterday was the best day ever! My family and I began our ski vacation.
Overloaded sentences
An overloaded sentence is one that squashes too much information together and, as a result, becomes hard to understand for readers.
The mistake:Â Youth league coaches need to understand that the education of a child is a big undertaking and should be done with care and consistency so that the child can gain maximum benefit from each training in order to set a solid foundation for any follow-up teaching.
Why itâs wrong:Â A good sentence focuses on one idea. The example above wanders around and takes too much mental effort before understanding the point.
The correction:Â Youth league coaches need to understand that the education of a child is a big undertaking. It should be done with care and consistency. That way, children can get the most from each training and set a solid foundation for any future teaching.
Related reading:Â An Introduction to AI Writing Software
Lowering the number of grammar mistakes in your writing
They say rules are meant to be broken â and weâd agree, as long as one is talking about the core grammar rules. Sometimes a missing comma or random sentence splice can make good writing great! So donât be afraid to follow your intuition. If youâre having fun, chances are your reader will be, too.
(For the words that matter most, take no chances! Make sure youâre using Writer.)
Common grammar mistakes FAQ
What is a grammatical error?
A grammatical error refers to an occurrence of faulty, unconventional or controversial usage, such as a dangling modifier or possessive noun errors. Grammar errors are also called usage errors.
What are examples of grammatical errors?
- Verb tense errors
- Faulty sentence structures
- Punctuation mistakes
- Overuse of adverbs
- Passive voice misuse
- Dangling participles
How do you identify grammatical errors?
You can identify grammatical errors by using a grammar checker to find and fix errors, improve word usage, verb tense, and punctuation for English text.
What are the 10 most common grammar mistakes?
Using millions of data points from Writer subscribers, we identified 10 common grammar mistakes:
- Letâs vs. lets
- Its vs. itâs
- Your vs. Youâre
- May vs. Might
- Lay vs. Lie
- Affect vs. Effect
- To vs. two
- There vs. their vs. theyâre
- Loose vs lose
- Peek vs. peak
What are three most common sentence errors?
- Run-on sentences
- Sentence fragments
- Overloaded sentences