Most people learning to write will make mistakes, and learning to spot common mistakes is a key to improving your writing. While grammar rules are helpful, the language has many exceptions, and some of the rules are tricky. In addition, we often speak in a grammatically incorrect way, making it difficult to write correctly. If you want to improve your English writing skills, you need to ask, “What are some common grammar mistakes in English?” Here are seven of the most common English grammar mistakes and explanations to help you avoid them in your own writing.
1. Subject-Verb Agreement
Errors in subject-verb agreement are some of the most common English grammar mistakes. Because English verbs don’t have gender, subjects and verbs only must agree in number. While this sounds simple, it can be complicated when sentences have compound subjects or verbs.
Singular Subjects Require Singular Verbs, while Plural Subjects Require Plural Verbs
The simplest rule regarding subject-verb agreement is that a singular subject requires a singular verb, while a plural subject requires a plural verb. Here are some examples of singular vs. plural subjects:
- Dog/dogs
- Man/men
- She/they, I/we
These are examples of singular vs. plural verbs:
- Calls/call
- Talks/talk
- Compares/compare
- Finds/find
To pair these properly, you would write a sentence like this:
- The man talks to his wife about their dinner plans.
- The men talk to their employer about problems at the job site.
For most verbs, the singular verb has an ending of -s, -es, or -ies, while the plural verb does not. There are two commonly used verbs that are an exception. These are:
- Is/are
- Has/have
Subject-Verb Agreement for Compound Subjects
For sentences with compound subjects, the verb you use depends on the conjunction used to join the subjects. If you use “and” to connect a compound subject, you use a plural verb. For example:
- Susan and Sam walk to the store together every Saturday afternoon.
In this case, both Susan and Sam are walking, so you use a singular plural verb (walk).
However, if you join a compound subject with the conjunction “or,” the rule changes. In this case, the verb agrees with the number of the subject that ends the list. For instance:
- Joe or Melva attends each home game while the other stays home.
Since the subjects are joined using or, nor, or but, the verb only agrees with Melva, which is singular, and thus the verb is singular. However, if you said:
- Neither your dog nor your cats like it when I come over.
Here, cats is the subject immediately following nor, so the verb must also be plural.
Unique Exceptions
In addition to these primary rules, there are a few exceptions to follow when making your subjects and verbs agree. These are:
- Most of the time, collective nouns such as family, team, or staff use a singular verb.
- The team waits patiently in the locker room for the starting bell. Even though a team is made up of multiple people, the collective noun is singular.
- You, even though it typically refers to one person, is a singular pronoun and takes a singular verb.
- You are a good friend.
- Indefinite pronouns, which include everyone, each, and someone, are singular and take singular verbs.
- Everyone walks slowly around that blind corner. Everyone is an indefinite pronoun, so it uses the singular verb walks.
- If you add additional nouns using phrases like such as or in addition to, the verb matches the subject, not the noun following this phrase.
- Example: Dave, in addition to his sisters, is allergic to peanuts. Dave is singular, as is the verb is.
2. Misplaced Apostrophes
Many English grammar common mistakes involve punctuation, and apostrophes tend to be a bit tricky for many people. The rules for proper apostrophe use are fairly simple, but implementing those rules can create some challenges.
Apostrophes in Contractions
The first rule for apostrophes is their use in contractions. When you combine two words, such as do and not, you typically place the apostrophe in the place where the missing letter would be (don’t). Some common contractions that follow this rule are:
- Can’t
- Won’t
- Isn’t
- I’ve
- I’ll
- You’ve
- He’ll/she’ll
- We’re
- They’re
- We’ve
- It’s
When you take out a letter to make a contraction, use an apostrophe to show it.
Use Apostrophes to Show Possession for Nouns
Apostrophes also show possession for nouns. If the noun is singular, you add an apostrphe and the letter “s” to show possession. Most of the time, you do this even if the word ends in “s.” Here are some examples:
- Dog’s
- Class’s
- Computer’s
- Sarah’s
The exception is proper nouns ending in “s.” For these, you can either add an apostrophe “s” or just an apostrophe. Both are grammatically correct.
- James’s
- James’
If a plural noun ends in “s,” then you add an apostrophe but no “s.” For example:
- Parents’
- Ladies’
- Weeks’
- Dogs’
However, if plural noun doesn’t end in “s,” then you simply use an apostrophe and “s” like singular nouns.
- Men’s
- Children’s
- Mice’s
Notice, however, that these rules apply only to nouns. Pronouns all have their own possessive forms without an apostrophe. These include:
- His
- Her
- Their
- Our
3. Run-On Sentences
Run-on sentences occur when two independent clauses run together without the proper punctuation or a conjunction. This common mistake occurs because spoken English involves running several sentences together quickly to make conversation. However, in written English, it’s a mistake.
Here is an example of a run-on sentence:
- I was tired I went to bed.
In this sentence, there are two independent clauses: “I was tired” and “I went to bed.” They can’t be joined without something to join them.
There are three ways to join two independent clauses accurately. You can:
- Add a coordinating conjunction (and, but, or, nor, for, etc.) and comma
- Add a subordinating conjunction (because, since, while, when, etc.) and no comma
- Add a semicolon and no conjunction
Here’s how this might look:
- I was tired, so I went to bed.
- I was tired even though I went to bed.
- I was tired; I went to bed.
One common mistake involving run-on sentences is called a comma splice. This involves adding just a comma between the independent clauses, as in:
- I was tired, I went to bed.
Here, you need a conjunction or a different structure, or the sentence is still wrong.
4. Confusing Its vs. It’s
Many people get confused between it’s the contraction and its the possessive pronoun. Because these two words are homophones, or words that sound the same but are spelled differently, they are easy to confuse.
It’s with an apostrophe is always the contraction for it is. The apostrophe replaces the missing letter.
- It’s common to make grammar mistakes in writing.
Its with no apostrophe is a possessive pronoun that means “belonging to it.” Even though possessive nouns have apostrophes, possessive pronouns do not.
- The bird gave its babies a fresh worm for breakfast.
If you can remember that the apostrophe shows missing letters in contractions and possessive pronouns never have an apostrophe, then you will avoid this common English grammar mistake.
5. Overusing Commas
Comma rules can be tricky to learn, and many people fall victim to using too few. Yet there’s another common issue, and that’s the overuse of commas. Either is a mistake, but overusing commas makes your writing seem choppy and makes it harder to read. Learning comma rules and not throwing commas into your writing if they aren’t needed will help you avoid this error.
Commas in Lists
The most common time to use a comma is in a list. If you’re listing three or more items, you will separate each one with a comma.
- Please call your brothers, sisters, and grandparents to tell them the good news.
Similarly, if you have a list of adjectives before a noun, they will usually have a comma. If the adjectives are equally important and can be switched without changing the meaning of the sentence, put a comma between them.
- The tired, cranky toddler needed his nap.
In this sentence, tired and cranky are equally descriptive of toddler, so they need a comma. Sometimes, you won’t use a comma between adjectives. If one adjective must precede the verb, such as a color word, you won’t use a comma. For example:
- The fluffy brown bunny hopped toward the hutch.
Here, it would not make sense to switch the adjectives fluffy and brown, so the sentence doesn’t need a comma.
Commas to Combine Sentences
When combining two independent clauses using a coordinating conjunction, such as and, use a comma.
- The class laughed hard, thinking it was a joke, but the teacher still gave them the pop quiz.
Commas in Introductory or Nonessential Phrases
Sometimes, you will add a nonessential phrase to your sentence to add clarity or explain more about a concept. Similarly, you may introduce your sentence with an introductory word or phrase. In both of these instances, set the phrase apart using a comma.
- The dog, the one with the black spots, barked loudly.
In this sentence, the phrase “the one with the black spots” adds clarity but is not fully necessary for the sentence to make sense.
- First, open the door for your classmates.
The introductory word first is set off from the rest of the sentence.
The rule surrounding introductory phrases is a bit more difficult. If the introductory phrase is a clause, which means it has a subject and verb, then it needs a comma. Similarly, if the introductory phrase includes a verb or verb form, such as an infinitive or participial, then it needs a comma. Finally, if an introductory phrase is four or more words, then it needs a comma. Shorter introductory phrases don’t need commas.
- Barking wildly, the dog got his owner’s attention.
Here, you use a comma because the introductory phrase includes a participial (barking.)
- A popular and well-known celebrity, George Clooney has starred in multiple blockbuster hits.
Here, the introductory phrase is four or more words.
- After dinner the child asked for a story.
Here, the introductory phrase is only two words, so no comma is necessary.
Commas to Set Apart Certain Words
Certain words always have commas to set them apart from the rest of the sentence. The words yes and no are examples of this. A name used in direct address in the sentence is offset by a comma as well. In addition, party affiliations, religious affiliations, and academic titles are set off by commas.
Here are examples of each of these rules:
- Yes, we will be there for your party.
- Actually, Dad, I don’t think we need to pick up milk since Mom bought some yesterday.
- We are pleased to welcome John Taylor, PhD., to speak at our convention.
Other Comma Rules
There are a few additional times when you need commas. These rules include:
- Separate similar words with a comma for clarity. For example, if you have to repeat the verb in a sentence, divide the two usages with a comma:
- What he is, is a thief.
- Use a comma to end or introduce direct quotes.
- “Please go to bed,” said the tired mother.
- The excited player said, “Coach, put me in!”
Examples of Unnecessary Commas
Understanding the proper use of commas will help you avoid unnecessary ones in your writing, but you may still feel tempted to use one when you don’t actually need it. Looking at examples of unwanted commas may also help. Here are some times when sentences do not need commas:
- Never use a comma to separate a subject and verb, including cases of compound verbs.
- Incorrect: The watch you found, is Sarah’s.
- Correct: The watch you found is Sarah’s.
- Incorrect: John is waiting outside, and is getting impatient.
- Correct: John is waiting outside and is getting impatient.
- Separating pairs that are joined with a coordinating conjunction.
- Incorrect: Either you are with us, or against us.
- Correct: Either you are with us or against us.
- Separating a beginning independent clause from an ending dependent clause that starts with a subordinating conjunction
- Incorrect: I got a bad grade, because I forgot to study for the final.
- Correct: I got a bad grade because I forgot to study for the final.
- Separating essential parts of the sentence from the rest of the sentence.
- Incorrect: My parents discouraged me from attending the university, that was near our home.
- Correct: My parents discouraged me from attending the university that was near our home.
6. Incorrect Word Usage
The English language is full of words that are very similar to one another or are commonly misused in spoken English. Some of the most common English grammar mistakes involve incorrectly using these words. Some of the most common incorrectly used words include:
- Advice: Noun, meaning opinion or information given to someone
- Advise: Verb meaning to give advice to someone
- Affect: Verb meaning to influence
- Effect: Noun meaning the result of something
- Complement: To complete something
- Compliment: To give someone praise
- Except: The exclusion of something
- Accept: Verb meaning to receive
- Everyday: Adjective meaning something that is common or ordinary
- Every day: Adverb meaning every single day
- Good: Adjective used to describe nouns
- Well: Adverb used to describe verbs
- Lose: A verb meaning to misplace an item
- Loose: An adjective meaning something that is not tight
- Principal: The person who heads up a school
- Principle: A belief
- Than: Used to compare two items
- Then: Used to show sequencing or passing of time
- There: Preposition that shows location
- Their: Possessive plural pronoun
- They’re: Contraction for “they are”
- To: Preposition
- Too: Adverb
- Two: A number
- You’re: Contraction for “you are”
- Your: Possessive plural pronoun
7. Lack of Parallel Structure
The final common English grammar mistake to avoid is a lack of parallel structure. Parallel structure means using the same form of a word or style of writing when listing items. For example:
- The children ran to the park, jumped on the climber, and slid down the slide.
In this sentence, each item in the list of activities the children did starts with a past-tense verb followed by a prepositional phrase. It is parallel in structure. In contrast:
- The children ran to the park, jumping on the climber, and sliding down the slide.
While this might sound fine to your ear, the verb ran and the verbs jumping and sliding are not the same structure, so this sentence lacks parallel structure.
In simple lists, parallel structure errors are fairly easy to spot, as long as you are thinking about what you’re writing.
- Incorrect: She liked doing art, playing piano, and to go to the library.
- Correct: She liked doing art, playing piano, and going to the library.
- Incorrect: Samantha’s grades were good because she studied hard, completed her assignments on time, and her motivation was excellent.
- Correct: Samantha’s grades were good because she studied hard, completed her assignments on time, and exhibited excellent motivation.
However, parallel structure is trickier when the lists aren’t so simple, such as if you have a list of clauses. For example:
- She told her children that they should wake up early, that they needed to do their chores, and then they could go outside to play in the afternoon.
The last item on the list, then they could go outside to play, is not parallel with the rest because it does not start with that. Instead, the sentence should read:
- She told her children that they should wake up early, that they needed to do their chores, and that they could go outside to play in the afternoon.
Make Your Writing Stronger by Avoiding These Common English Grammar Mistakes
Writing in English can be tricky with all of the rules and exceptions to those rules. As you strive to make your writing stronger, keep this list handy. By avoiding these errors, you can write clear, strong paragraphs in English.
