10 common grammar mistakes writers make [Infographic]
Editor’s note: This article was reviewed and updated in July 2026 to meet Expert Editor’s latest editorial standards.
This infographic is based on our previous post The 30 Most Common Grammar Mistakes (and How to Avoid Them).
Great writing doesn’t require perfect grammar, and occasionally grammar rules can (and should) be broken.
A writer is better served by being engaging, persuasive, and entertaining than by being a stickler for English rules.
However, a solid understanding of grammar is essential for any writer, whether an author or student. Common errors detract from the reading experience and cast a shadow on the writer’s competence and concern for their work. If the grammar is poor, it also makes it much harder for your writing to be compelling.
Here are 10 common grammar mistakes that writers make and how you can avoid them.
The best way to convey ideas in your writing is to use good grammar. Proper grammar gives your writing a professional, confident glow, whereas grammatical mistakes signal to readers that your grasp of English is uncertain. Although English is rife with inconsistencies, its rules carry the weight of centuries of use. The grammar of the English language has evolved over many hundreds of years to arrive at where it is today.
English belongs to the West Germanic branch of languages — a subfamily that includes German, Dutch, and Frisian. When the Anglo-Saxon peoples landed in Britannia in the mid-5th to 7th centuries, they brought with them their dialects, which evolved dramatically over the following millennium. English grammar was altered by Norse-speaking invaders in the 9th and 10th centuries. Norman-French-speaking invaders in the 11th century further shaped English vocabulary and structure. In the 16th and 17th centuries, scholars and historians codified English grammar more formally. William Bullokar published works on English grammar in 1586 — among them a text widely regarded as one of the earliest printed English grammars.
Even today, modern English grammar is constantly being challenged by globalization and the internet. As English is the dominant language on the internet, many pages on the web are written in English without proper editing. If bad grammar is so ubiquitous, then proper grammar will separate you from the rest.
What are the ten most common grammar mistakes in the English language? Let’s go through each individually.
There/Their/They’re
These words sound alike (they are homophones) but their meanings are entirely different. “There” indicates a location. “Their” is a possessive adjective, indicating a relation to “them” or “themselves”. “They’re” is a contraction of “they are”.
The comma splice
When a comma connects two independent clauses, this is a comma splice. A run-on sentence is similar to a comma splice because a run-on sentence also joins two complete sentences together, but with no punctuation in between.
Fixing a Comma Splice
“The teacher asked a question about comma splices, the student was befuddled.”
- Put a period in between the two sentences.
“The teacher asked a question about comma splices. The student was befuddled.”
- Use a semi-colon instead of a comma.
“The teacher asked a question about comma splices; the student was befuddled.”
- Coordinating conjunction
“The teacher asked a question about comma splices, but the student was befuddled.”
- Subordinating conjunction
“The teacher asked a question about comma splices, although the student was befuddled.”
It’s vs. Its
It’s contains an apostrophe because it is a contraction of “it is” — for example, “It’s raining.”
Its is the possessive form of it — for example, “The cat licked its paw.”
The split infinitive
A split infinitive occurs when an adverb or other word is placed between “to” and the verb — as in “to boldly go.” Though widely treated as a grammar rule, the split infinitive was discouraged but not forbidden by Henry Alford in his 1864 book, A Plea for the Queen’s English.
Your vs. You’re
“You’re” is a contraction, which can be expanded to “you are” — for example, “You’re a great writer.”
“Your” is a possessive pronoun — for example, “Your writing has improved.”
Passive voice
This occurs when the writer makes the object of the sentence into the subject. This has the effect of weakening the action. A verb is in the passive voice when the subject is acted upon by the verb.
Passive voice: “The roses in the garden were gathered by me.”
Active voice: “I gathered the roses in the garden.”
Lose vs. Loose
“Lose” is a verb meaning to be deprived of something or to fail to win — for example, “Don’t lose your keys.”
“Loose” is an adjective describing something not tightly bound — the opposite of “tight”. For example: “The knot came loose.”
Literally
The word literally means “in a literal sense or manner”. However, “literally” is now also widely used for emphasis or exaggeration; so much so that Merriam-Webster has added a secondary meaning to reflect this shift. This is an example of living language adapting in real time.
Affect vs. Effect
Whereas “affect” is a verb meaning “to change or influence”, “effect” is a noun indicating that a change has occurred.
“Effect” can also be a verb, meaning “to cause something to happen; to bring about.”
Who vs. That
Using “that” when referring to a person makes the person seem less human. Use “who” instead — for example, “The writer who finished first” rather than “The writer that finished first.”
However, you can use “whose” — the possessive form of “who” — to refer to both people and things. This is because English does not have a possessive form of “that”. You can say, “The book whose cover is a shade of deep magenta”, but you wouldn’t say, “The book who is sitting on the table.”
And there you have it: ten of the most common grammar errors in English, all in one place.