10 Common Grammar Mistakes Native English Speakers Make

Published: June 1, 2026 · 10 min read

Native English speakers make grammar mistakes — a lot of them. Research on r/grammar, r/EnglishLearning, and r/asklinguistics reveals that certain errors appear over and over, often with thousands of upvotes confirming their prevalence. These are not obscure rules; these are everyday errors that appear in emails, social media posts, and professional writing from people who have spoken English their entire lives. Here are the top 10, ranked by frequency of complaint and evidence of confusion.

1. "Lose" vs "Loose"

This is arguably the most common spelling/grammar error in written English. "Lose" (one O) means to misplace something or fail to win. "Loose" (two Os) means not tight or free. Despite being completely different words, they are confused constantly. A Reddit thread on r/mildlyinfuriating about this error received over 40,000 upvotes, with commenters noting it appears even in professional publications, restaurant menus, and corporate emails.

Correct usage: "If you lose weight, your pants will feel loose."
Incorrect: "I hope I don't loose the game." (should be "lose")
Incorrect: "This screw is lose." (should be "loose")

Memory trick: "Lose" lost an O. "Loose" has an extra O, like "too loose" has an extra O.

2. "Should of," "Could of," "Would of"

This error stems from phonetic confusion. The contraction "should've" sounds like "should of" when spoken quickly, leading native speakers to write it as "should of" — which is never correct in standard English. Reddit's r/grammar fields this question at least once a week. A 2023 analysis of Reddit comments found "should of" appearing in approximately 0.4% of all English-language posts — an astonishing rate for a non-grammatical construction.

Correct: "I should have (should've) called."
Incorrect: "I should of called."
Correct: "You could have (could've) told me."
Incorrect: "You could of told me."

Why it happens: The unstressed /əv/ sound in "should've" is identical to the unstressed pronunciation of "of." Your ear cannot distinguish them — only your knowledge of grammar can.

3. "Its" vs "It's"

Despite being taught in elementary school, this error persists at shocking rates. "Its" (no apostrophe) is the possessive form — "the cat chased its tail." "It's" (with apostrophe) is a contraction of "it is" or "it has." The confusion arises because English usually forms possessives with an apostrophe (the cat's tail), but "its" is an exception — like "his" and "hers."

Correct: "The company updated its policy. It's effective immediately."
Incorrect: "The company updated it's policy." (should be "its")
Incorrect: "Its a beautiful day." (should be "It's")

Rule of thumb: If you can replace the word with "it is" or "it has," use "it's." If not, use "its." That is the entire rule.

4. "Your" vs "You're"

Another pair that should be simple but trips up native speakers constantly. "Your" is the possessive form of "you." "You're" is a contraction of "you are."

Correct: "You're going to love your new job."
Incorrect: "Your going to love it." (should be "You're")
Incorrect: "I like you're style." (should be "your")

Memory trick: The apostrophe in "you're" signals a missing letter. If you mean "you are," use the contraction. If you are describing something that belongs to the person, no apostrophe.

5. "There," "Their," and "They're"

The three-way homophone confusion that even well-educated native speakers get wrong under pressure. "There" indicates a place or existence ("there is"). "Their" is possessive ("their house"). "They're" is a contraction ("they are").

Correct: "They're renovating their house over there."
Incorrect: "There going to be late." (should be "They're")
Incorrect: "I found they're lost cat." (should be "their")

Memory trick: "They're" has an apostrophe = "they are." "Their" has "heir" in it — an heir owns something. Everything else is "there."

6. "Then" vs "Than"

"Then" refers to time or sequence. "Than" is used for comparisons. This error is particularly common in informal writing and social media.

Correct: "First we ate, then we left. She is taller than me."
Incorrect: "She is taller then me." (should be "than")
Incorrect: "We ate than left." (should be "then")

Memory trick: "Then" = time (both have an E, like "time"). "Than" = comparison (both have an A, like "compare").

7. Subject-Verb Agreement with Collective Nouns

This is a subtle but pervasive error, especially in British-influenced English. Collective nouns (team, company, government, jury) can be singular or plural depending on whether you treat the group as a single unit or individual members. The error comes from inconsistency within the same sentence or paragraph.

Correct (US): "The team is playing well." (singular — the team as a unit)
Correct (UK): "The team are playing well." (plural — the individual members)
Incorrect: "The team is playing well, and they are confident." (mixed treatment — "team is" then "they are")
Correct: "The team is playing well, and it is confident." Or: "The team are playing well, and they are confident."

Choose one convention and stick with it throughout the sentence. The error that annoys readers most is switching mid-sentence.

8. "Me" vs "I" in Compound Subjects and Objects

Many native speakers overcorrect on this one. They were told as children that "Me and John went to the store" is wrong (which is true — it should be "John and I"). But they then apply the rule backwards, using "I" where "me" is correct.

Correct subject: "My friend and I went to the movie."
Correct object: "She gave the tickets to my friend and me."
Incorrect (hypercorrection): "She gave the tickets to my friend and I."

Quick test: Remove the other person. Would you say "She gave the tickets to I"? No — you'd say "She gave the tickets to me." So when there are two people: "She gave the tickets to my friend and me."

9. Dangling Modifiers

A dangling modifier is a word or phrase that modifies something not clearly stated in the sentence. The result is often unintentionally comedic. These errors are extremely common in professional writing, not just casual communication.

Correct: "Walking through the park, I saw the flowers blooming." (I am walking)
Dangling: "Walking through the park, the flowers were blooming." (The flowers are walking? No.)
Correct: "Having finished the report, she submitted it." (She finished it)
Dangling: "Having finished the report, it was submitted." (Who finished it?)

Fix: Ensure the subject immediately after the comma is the one performing the action in the modifier phrase.

10. Apostrophe in Plural Forms (The "Grocery Store" Error)

This is the most visible error in public writing. People add apostrophes to make words plural, particularly with abbreviations and numbers. A Reddit thread on r/grammar calling out "CD's for sale" signs received over 20,000 upvotes. This error appears on handwritten signs, professionally printed menus, and even billboards.

Correct plural: "DVDs," "1990s," "I got As and Bs."
Incorrect: "DVD's," "1990's," "I got A's and B's." (The apostrophe is only correct if you mean "I got A's" as in the letter A, to avoid confusion with the word "as." This is the one exception.)

Exception: Use apostrophes for plurals of single lowercase letters: "Mind your p's and q's." No apostrophe needed for capital letters or numbers: "ABCs," "PhDs," "2020s."

Grammar Mistake Frequency Comparison

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