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English grammar and punctuation rules are not set in stone. As the years go by, they change and evolve along with the language itself. This is a good thing, in my opinion.
However, that doesn’t mean there is no value in learning the current rules and using them correctly in the meantime. The problem is that after we leave school, we almost immediately start forgetting what we learned unless we write, edit, or teach English professionally.
Often this grammar amnesia is slight (needing to refresh your memory about the words that don’t follow the “i before e” rule, for example), but sometimes it is surprisingly severe and widespread.
So, I’m offering this short refresher on the top six English grammar and punctuation rules I see ignored or misused most often:
1. Don’t use an apostrophe to make something plural
Whether it’s an ad for a DJ spinning new wave hits from the 1980’s; a cute sign on the front of your neighbor’s house that reads: The Schmidt’s; or the sign at the grocery store that offers “Avocado’s” for $1.50 per pound, all of them are using apostrophes incorrectly.
Apostrophes are only used for two things:
- To indicate possession: The Schmidts’ house was beautiful. (The house belongs to the Schmidts.)
- In contractions (e.g., aren’t, isn’t, they’re, I’m, etc.)
That’s it. The only exception to this is with single lowercase letters used in a sentence, like “Don’t forget to cross your t’s and dot your i’s.” To be clear, the apostrophes in this exception don’t make these letters plural (the “s” does that). They just make the sentence easier to read and understand.
2. Stop using single quotation marks instead of double quotation marks
There’s a reason why we use two fingers on each hand, not one, when we do air quotes. Single quotation marks are only used for two things:
1. Putting a direct quote or the title of a short work in an article headline or blog title
‘I Did It for My Kids,’ Says Heroic Mom
2. Putting a direct quote or the title of a short work inside another direct quote
“My favorite song right now is ‘Anti-Hero’ by Taylor Swift,” Mara said.
3. Assure, ensure, and insure are not interchangeable
Insure should only be used when referring to insurance policies and coverage (auto insurance, home insurance, life insurance, etc.). That is easy to remember since they both start with “insur.”
The cost to insure homes against flood damage has skyrocketed in communities along the banks of the Mississippi River.
Assure and ensure are a little more difficult because their meanings are somewhat similar. One way to tell the difference is to remember that assure, like reassure, is typically used when referring to people or animals and ensure is typically used when referring to actions or guarantees.
The City assured residents of its intent to distribute relief funding within the next 30 days.
The bill will ensure that climate change is put in the spotlight every year.
4. Use “e.g.” when listing examples, not “i.e.”
E.g. is an abbreviation of “exempli gratia,” which means “for example” and is used to introduce one or more examples.
Healthy exercise (e.g., riding a bike, jogging, hiking, etc.) will help you live longer.
I.e. is an abbreviation of “id est,” which means “that is,” “in other words,” or “in essence” and is used to provide clarification.
I am a pescatarian (i.e., a vegetarian who also eats fish).
To avoid using the wrong abbreviation, I simply remember that e.g. starts with the same first letter as “example(s)” and i.e. starts with the same first letter as “in other words.” And don’t forget to put a comma after the second period in both abbreviations!
5. Hyphens, en dashes, and em dashes are not interchangeable (with one exception)
A hyphen (-) is used to join words or parts of words together (long-term, editor-in-chief, trans-Atlantic, etc.). It can also be used instead of an en dash in ranges of numbers. It should never be used to set off separate clauses or phrases within a sentence (that’s what an em dash is for).
An en dash (–) is longer than a hyphen but shorter than an em dash. It is used to show ranges of numbers, including dollar amounts, years, times, page numbers, etc. It should never be used to set off separate clauses or phrases within a sentence. It is primarily used in formal publications and can be replaced by a hyphen if preferred. Just remember to be consistent in what you use!
The community meeting was scheduled from 4:30–7 p.m.
New hires earn $21.50–$25 per hour.
An em dash (—) is stronger than a comma but weaker than a period or semicolon. They are used to:
- indicate a pause in a sentence
- set off a separate clause, word, or phrase within a sentence
- add emphasis or amplify an idea
- set off the source of a direct quotation
Dark, leafy greens—such as spinach, kale, and chard—are an important part of a healthy diet.
I opened the door, and there she stood—my long-lost sister.
“Try not to become a man of success, but rather try to become a man of value.”—Albert Einstein
Use of em dashes has increased in recent years, thanks to AI writing tools like ChatGPT, Google Gemini, and Perplexity. Although AI does use em dashes correctly in the copy it generates, it sometimes uses them a little too often in a single piece of writing, in my opinion. Always proofread any AI-generated copy you plan to use and ask yourself if a comma, colon, or semicolon might work better than an em dash.
6. Get those homophones straight
Homophones are words that sound the same but have different meanings, such as “their, there, they’re,” “too, to, and two,” and “its and it’s,” and their misuse has really taken off in the last decade.
The best way to avoid using the wrong word is to make sure you actually understand the difference between them.
Get Free Proofreading Assistance
To help eliminate these types of common mistakes from your writing, I recommend downloading and using Grammarly.com’s free automated writing assistant plug-in for your computer or web browser. It will highlight basic grammar and punctuation errors as you write and show you how to correct them.
You can also run your copy through an AI tool like ChatGPT, Gemini, and Perplexity and ask it to correct or highlight any grammar mistakes for you. Note that there is a difference between British and American English grammar rules, so you will need to specify which one AI should use in your prompt depending on who your audience will be. (Example prompt: Proofread this text and correct any American English grammar mistakes.)
This article was originally published on January 6, 2023, and was updated by the author on January 9, 2026.
About the Author
Jilayne Jordan is the Communications and Graphics Specialist at Camoin Associates. She has over 30 years of professional experience writing and copyediting a wide variety of digital and print publications for internal and external audiences. She holds a Bachelor of Arts degree in Journalism from Humboldt State University with an emphasis in public relations.
