Common Grammatical Errors That Make Editors Cringe

Wednesday, January 243 min read

Everyone makes mistakes, especially when it comes to grammar. These slips typically consist of errors in punctuation, syntax, and word choice. While small mistakes are nothing to lose sleep over, repeated grammatical errors can make your work look unpolished and unprofessional. Even worse, some mistakes can change your intended meaning and lead to confusion. Let’s go over some of the most common grammatical errors in the English language and how to avoid them.

Your vs. You’re, etc.

Homophones are words that have the same pronunciation but different meanings, origins, or spellings. These make up some of the most common errors in English, with “your” vs. “you’re” as a prime example. “Your” is a possessive pronoun, a way of indicating that something belongs to another person. “You’re” is a contraction of “you are,” and is not used to indicate possession. Similarly, folks often mess up “who’s” vs. “whose” (“who’s” is a contraction of “who is,” and “whose” is the possessive form of “who”) and “they’re” vs. “their” (“they’re” is a contraction of “they are,” and “their” is the possessive form of “they”).

That vs. Which

These words can function as several parts of speech, but here we are using them as relative pronouns. They introduce relative clauses that provide additional context to a sentence. For example: “This is the house that Jack built.” The correct relative pronoun to use depends on what you are referring to, which is how people often get tripped up here. Use “that” to introduce a clause that adds necessary information to a sentence, and use “which” to introduce a clause that adds detail but isn’t critical to the sentence. Compare the following:

Don’t use the milk that has spoiled.

I also got this creamer, which is made from almond milk.

We use “that” in the first sentence because it is giving critical information — you wouldn’t want anyone to get sick from spoiled milk. With the second sentence, the explanation following the comma is nice to know, but it isn’t essential. It’s a nuanced judgment, but another important thing to note when deciding between “that” and “which” is to always precede the “which” clause with a comma.

Then vs. Than

As with the possessive pronoun examples above, “then” and “than” are homophones, which makes them easy to swap. Here’s how to differentiate: “Then” refers to when something will happen, while “than” is used to compare people or things.

Each and Every

This may seem a bit nitpicky, but the goal is for you to be a grammar pro. “Each” refers to two items. “Every” refers to three or more items. Furthermore, you should use “each” when referring to the individual items in a group, and use “every” to refer to a group as a whole:

Each of my two dogs got a treat after our walk.

Every one of my cousins is coming to my wedding.

The difference here is slight, but it exists: Each of the two dogs got their own treat, whereas all of the many cousins are going to the wedding.

Possessive Nouns

A possessive noun is the version that indicates ownership. An apostrophe and the letter “s” is added to turn the noun into a possessive, but folks frequently put the apostrophe in the wrong place. For a singular possessive noun, the apostrophe goes before the “s”: “Susanne’s cat.” For a plural possessive noun (ending in “s”), the apostrophe goes after the “s”: “the students’ school.” For a singular possessive noun that ends in an “s,” you would still add an apostrophe and the letter “s”: “James’s car” or “the actress’s car” (think about how you pronounce these to help you remember the double “s”).


The comma is likely the most versatile punctuation mark, but because we sprinkle them into writing so liberally, it can be easy to use them incorrectly. In general, they are used for separation and to create short pauses in sentences. They can separate items in a list, distinguish independent clauses, or note appositives (words used before or after nouns to fully describe them — see “that” vs. “which” above).

Incorrect: I bought cleaning supplies paper towels and bandages at Target.

Correct: I bought cleaning supplies, paper towels, and bandages at Target.

There is some debate between fellow word nerds about the Oxford comma — also known as the “serial comma” — which is the comma used after the penultimate item in a list of three or more items (i.e., the one after “paper towels” above). Some style guides dictate its use, but it is ultimately optional, and it depends on what and where you are writing. This cartoon is an apt explanation for why leaving out an Oxford comma can be confusing for your reader.

Featured image credit: LittleCityLifestylePhotography/ iStock

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