Recently I came across two articles on common grammar mistakes. One was written by Morgan Greenwald for Best Life and a second one by Amanda Zantal-Wiener for HubSpot. Here are many of the mistakes they highlighted as well as a few I added.

“Its” vs. “It’s”

It’s is a contraction of “it is.” Its is a possessive adjective.

Incorrect: Give the cat it’s dinner.

Correct: Give the cat its dinner.

Correct: It’s the cat’s dinner.

Misplaced commas

One of the most common comma errors is a comma splice or using a comma to merge two complete clauses when there should be a semicolon or a period.

Incorrect: Beth ate dinner, later she saw a movie.

Correct: Beth ate dinner. Later she saw a movie.

“To” vs. “Too.”

To is a preposition used to indicate movement or action. Too is a synonym for also or an adverb meaning more than desired.

Incorrect: I ate to much so I need too walk around for a little bit.

Correct: I ate too much so I need to walk around for a little bit.

Incorrect: May I have some coffee to?

Correct: May I have some coffee too?

“Their,” “They’re,” and “There”

Their is a possessive adjective meaning people own something.

They’re is a contraction for they are.

There is an adverb indicating a specific place or position.

Incorrect: Their walking there bicycles to the store over they’re.

Correct: They’re walking their bicycles to the store over there.

“Irregardless” vs. “Regardless”

Irregardless is not an actual word. The correct word meaning without paying attention to the situation is regardless.

Incorrect: Irregardless of who pays, I don’t want to eat there. It’s too expensive.

Correct: Regardless of who pays, I don’t want to eat there. It’s too expensive.

“There’s” and “Here’s”

There’s and here’s are contractions of there is and here is; therefore they are used with singular nouns.

Incorrect: Here’s six new cars.

Correct: Here are six new cars.

Correct: Here’s a new car.

“Based off” vs. “Based on”

The correct phrase is based on, not based off. An easy way to remember this is a base is part of something that everything else in on.

Incorrect: Based off this data, that computer is the better deal.

Correct: Based on this data, that computer is the better deal.

“Your” vs. “You’re”

You’re is a contraction of you are. Your is a possessive pronoun.

Incorrect: Your to take this to you’re teacher.

Correct: You’re to take this to your teacher.

Shortening decades properly

The correct way to shorten decades is to place the apostrophe before the number, not afterwards.

Incorrect: I lived in Asia in the 90s.

Incorrect: I lived in Asia in the 90’s.

Correct: I lived in Asia in the ‘90s.

“That” vs. “Which”

If you can remove a clause from the sentence with changing the meaning of the sentence, then which is the word to use. If it changes the meaning of the sentence, then use that.

Incorrect: For classes which have a lab component, you must pay an extra fee.

Correct: For classes that have a lab component, you must pay an extra fee.

Incorrect: The blue pickup truck, that has automatic transmission, is a great deal.

Correct: The blue pickup truck, which has automatic transmission, is a great deal.

“All Right” vs. “Alright”

The correct spelling is all right. Alright is not grammatically correct.

Incorrect: Don’t worry about it. It’s alright.

Correct: Don’t worry about it. It’s all right.

“Already” vs. “All Ready”

Already is an adverb meaning prior to a specified time or as early as now. All ready means completely prepared.

Incorrect: We all ready delivered the flowers so the stage is already for the presentation.

Correct: We already delivered the flowers so the stage is all ready for the presentation.

“Affect” vs. “Effect”

Affect is a verb and effect is a noun.

Incorrect: The affects of this new software effects the energy output of the electrical system.

Correct: The effects of the new software affects the energy output of the electrical system.

“Lie” vs. “Lay”

Lay requires a direct object while lie does not. An easy way to remember them: pLAce – because lay involves placing something, and recLIne – because lie involves reclining.

Incorrect: I will lie a pillow on the sofa so that I can lay on it.

Correct: I will lay a pillow on the sofa so that I can lie on it.

“Let’s” vs. “Lets”

Let’s is a contraction of let us, and used in commands and suggestions. Lets is the present tense of the verb let, meaning “to allow.”

Incorrect: If my boss let’s me take off work, lets go to the ball game.

Correct: If my boss lets me take off work, let’s go to the ball game.

“Fewer” vs. “Less”

Fewer is used when items can be counted, such as apples and books. Less is used with singular mass nouns, things that cannot be counted, such as hair and sugar. One easy way to remember is fewer is usually used with nouns that have a plural form by adding “s” or changing letters in the word.

Incorrect: Because I had fewer money, I bought less snacks for the trip.

Correct: Because I had less money, I bought fewer snacks for the trip.

“Many” vs. “Much”

The same rules apply to many and much as with fewer and less. Many is usually used with things that can be counted while much is usually used with thing that cannot be counted.

Incorrect: How many food does it take to feed that much dogs?

Correct: How much food does it take to feed that many dogs?

Add a comma after a state name

When writing the name of a city followed by the state, there should be a comma before and after the state name.

Incorrect: The city of Orlando, Florida has many tourist attractions.

Correct: The city of Orlando, Florida, has many tourist attractions.

“Since” vs. “Because”

Since has two meanings. One is it refers to the cause of an effect. The second is it refers to the time some action began. Because refers only to the cause of an effect or a reason for doing an action.

“Then” vs. “Than”

Than is used to compare two things, while then refers to when an action takes place.

Incorrect: I’ll check the price of a room at the Hyatt; than I’ll see if it’s more expensive then the Marriott.

Correct: I’ll check the price of a room at the Hyatt; then I’ll see if it’s more expensive than the Marriott.

En Dashes vs. Em Dashes

The en dash “-“ or hyphen, has only two uses: to connect some compound words and to separate numbers. For other uses, such as a break in a sentence, use the em dash “—”.

Incorrect: I’ll mow the lawn today-if I can’t find the time, I’ll have my 12—year—old nephew do it.

Correct: I’ll mow the lawn today—if I can’t find the time, I’ll have my 12-year-old nephew do it.

Forgetting an Apostrophe

With an apostrophe, a noun becomes a possessive; but without one, it’s just a plural form of the noun.

Incorrect: This is Bobs book and that one is Shirleys.

Correct: This is Bob’s book and that one is Shirley’s.

i.e. vs. e.g.

These two abbreviations do not mean the same thing. First, “i.e.” means “that is” or “in other words.” But “e.g.” means “for example.”

Who vs. That

Who is for a person, and that is for a thing.

Incorrect: Bob is the person that sits at that desk.

Correct: Bob is the person who sits at that desk.

Who vs. Whom vs. Whose vs. Who’s

Who is a pronoun identifying a person.

Whom is also a pronoun identifying a person, but usually used with a preposition such as to or from.

Whose is used to assign ownership, as in whose is it.

Who’s is a contraction of who is.

Examples:  Who won the tennis match?

To whom do you want these flowers delivered?

Whose car is the blue one?

Who’s bringing the beer for the party?

Alot vs. A Lot vs. Allot

First, alot is not a word. If you wish to say many things or much of something, the words are a lot. The word allot means to set aside a certain amount of money.

Incorrect: We have alot of apples at home.

Correct: We have a lot of apples at home.

Correct: We will allot ourselves a $25.00 limit on gifts for the office.

Assure vs. Insure vs. Ensure

To assure is to promise or say something with confidence.

To ensure is to make certain.

To insure is to protect against risk by paying an insurance company.

Examples:  I can assure you she’s coming to the party.

Please ensure there is coffee and tea for our guests.

I need to insure my home and car against natural disasters.

Farther vs. Further

Farther is used when referring to physical distances, while further is used when referring to figurative or nonphysical distances.

Incorrect: Washington D.C. is further away from New York than Philadelphia.

Correct: Washington D.C. is farther away from New York than Philadelphia.

Incorrect: Have you made any farther progress towards your degree?

Correct: Have you made any further progress towards your degree?

NOTE: Further is preferred in British English in all cases.

Between vs. Among

The word between is used when referring to two things clearly separated, while the word among is used when referring things that part of a group or mass of objects.

Incorrect: You need to choose among the black cat or the orange one between all of the cats here.

Correct: You need to choose between the black cat or the orange one among all of the cats here.