10 Common Grammar Mistakes Students Make and How to Fix Them

Did you know that nearly half of all students lose marks due to simple grammar mistakes? Whether it’s a misplaced comma, incorrect subject-verb agreement, or the misuse of homophones, these errors can significantly affect a student’s grades and overall writing quality. Proper grammar is not just a requirement for academic success; it plays a vital role in shaping effective communication skills that will benefit students in their future careers. From writing essays and research papers to drafting emails or resumes, mastering grammar is essential.

In this article, we’ll explore the 10 most common grammar mistakes that students tend to make, and we’ll provide simple tips to help you avoid them. By the end of this guide, you’ll be equipped with the tools to improve your writing and avoid these common pitfalls.

1. Subject-Verb Agreement Errors

What is Subject-Verb Agreement?

Subject-verb agreement refers to the grammatical rule that the subject and verb in a sentence must agree in number. This means that a singular subject must be paired with a singular verb, and a plural subject must be paired with a plural verb.

Common Mistake

Many students struggle with subject-verb agreement, especially when the subject is separated from the verb by other words or phrases. For example:

• Incorrect: The team of players are practicing.
• Correct: The team of players is practicing.

In this example, “team” is a singular subject, so it should be paired with the singular verb “is.” The presence of the plural “players” can lead to confusion, but the subject remains singular.

How to Avoid

To avoid subject-verb agreement mistakes, always identify the subject of the sentence and determine whether it is singular or plural before selecting the verb. Here’s a quick tip: eliminate any intervening phrases or words between the subject and verb to focus on the subject itself.

For instance:

• Incorrect: The book, along with the notebooks, were on the table.
• Correct: The book, along with the notebooks, was on the table.

In this case, “book” is the singular subject, and the correct verb is “was.” Words like “along with” don’t change the subject’s number.

2. Misuse of Homophones (e.g., there, their, they’re)

What are Homophones?

Homophones are words that sound the same but have different meanings and spellings. They often lead to confusion in writing because even though they sound identical, their meanings are entirely different. This confusion is common among students and can drastically alter the meaning of a sentence if the wrong word is used.

Common Mistake

One of the most frequent homophone mistakes involves the misuse of “there,” “their,” and “they’re.” Despite sounding alike, these words have distinct meanings:

• There: Refers to a place or position (e.g., The book is over there).
• Their: Indicates possession (e.g., Their car is parked outside).
• They’re: A contraction of “they are” (e.g., They’re going to the concert).

Using the wrong homophone can change the intended meaning of a sentence, leading to confusion or misinterpretation. For instance:

• Incorrect: Their going to be late for the meeting.
• Correct: They’re going to be late for the meeting.

How to Avoid

To avoid misusing homophones, it’s helpful to remember a few mnemonic devices or context clues:

• There: Think of the word “here” within “there,” which also refers to a place.
• Their: Remember it contains the word “heir,” which relates to possession.
• They’re: Expand it to “they are” to see if the sentence still makes sense.

3. Incorrect Use of Commas

The Role of Commas in Writing

Commas are one of the most versatile punctuation marks in English, used to separate items in a list, set off introductory elements, or link independent clauses. Despite their frequent use, commas are also one of the most misused punctuation marks, leading to confusion in writing.

Common Mistake

Students often misuse commas in two primary ways: overusing them, which can create fragmented or unclear sentences, or underusing them, which can result in run-on sentences. For example:

• Incorrect: I bought apples, oranges and bananas. (Missing comma in a list)
• Correct: I bought apples, oranges, and bananas.

Another common mistake is placing a comma between two independent clauses without a conjunction, leading to a comma splice:

• Incorrect: She loves to read, she finishes a book every week.
• Correct: She loves to read, and she finishes a book every week. or She loves to read; she finishes a book every week.

How to Avoid

To use commas correctly, follow these basic rules:

• Lists: Use commas to separate items in a list of three or more items.
• Introductory Elements: Place a comma after introductory words, phrases, or clauses (e.g., After dinner, we went for a walk).
• Compound Sentences: Use a comma before conjunctions (and, but, or, nor, for, so, yet) when they join two independent clauses.

Reading your sentences out loud and pausing where you would naturally take a breath can help you determine where commas should go.

4. Confusion Between “Its” and “It’s”

Understanding “Its” vs. “It’s”

The confusion between “its” and “it’s” is one of the most common grammatical errors in student writing. Despite their similar appearance, these two words serve different purposes:

• “Its” is a possessive pronoun, meaning something belongs to or is associated with a thing (e.g., The dog wagged its tail).
• “It’s” is a contraction of “it is” or “it has” (e.g., It’s going to rain today).

Common Mistake

Students frequently mix up “its” and “it’s,” even in formal writing. This mistake can lead to sentences that are either grammatically incorrect or convey a different meaning than intended. For example:

• Incorrect: The cat licked it’s paws.
• Correct: The cat licked its paws.

In this example, “its” is the correct choice because it shows possession, meaning the paws belong to the cat.

How to Avoid

A simple trick to avoid this mistake is to expand “it’s” to “it is” or “it has.” If the sentence still makes sense, then “it’s” is correct. If it doesn’t, then “its” is the word you need. For example:

• It’s a beautiful day (expands to It is a beautiful day—correct).
• The tree lost it’s leaves (expands to The tree lost it is leaves—incorrect, so “its” should be used).

By keeping this trick in mind and proofreading your work, you can easily avoid this common grammar pitfall.

5. Misplaced Modifiers

What is a Misplaced Modifier?

A misplaced modifier is a word, phrase, or clause that is improperly separated from the word it describes. When modifiers are placed incorrectly, they can lead to confusing or humorous sentences because they appear to modify the wrong word or phrase.

Common Mistake

Misplaced modifiers often occur when the modifier is not placed next to the word it is supposed to modify. This can result in sentences that either don’t make sense or unintentionally change the meaning. For example:

• Incorrect: Running quickly, the finish line was crossed by the athlete.
• Correct: Running quickly, the athlete crossed the finish line.

In the incorrect sentence, the modifier “running quickly” seems to describe “the finish line,” which doesn’t make sense. Placing the modifier next to the subject “the athlete” clarifies the sentence.

How to Avoid

To avoid misplaced modifiers, always place the modifier as close as possible to the word it is meant to describe. When proofreading, check each sentence to ensure that modifiers are positioned correctly and that they modify the intended word or phrase. Rearranging the sentence to improve clarity is often necessary. For example:

• Incorrect: She served the dinner to the guests on paper plates.
• Correct: She served the guests dinner on paper plates.

The correct version clarifies that the dinner, not the guests, was on paper plates. Ensuring that your sentences are clear and modifiers are correctly placed will significantly improve the readability of your writing.

6. Run-On Sentences

Understanding Run-On Sentences

Run-on sentences occur when two or more independent clauses (complete sentences) are improperly joined without the correct punctuation. These errors typically happen when students fail to separate ideas with appropriate punctuation, leading to sentences that are long, confusing, and difficult to read.

Common Mistake

A run-on sentence often happens when a student combines multiple ideas into one sentence without using the proper connectors, such as conjunctions, commas, or periods. For example:

• Incorrect: I love reading books I can spend hours in the library without getting bored.
• Correct: I love reading books. I can spend hours in the library without getting bored.

In the incorrect example, two complete ideas are crammed into one sentence without proper separation, making it a run-on.

How to Avoid

To avoid run-on sentences, students should break up their ideas into shorter, clearer sentences. There are a few ways to do this:

• Use a Period: Separate independent clauses into distinct sentences.

Example: She enjoys playing tennis. She practices every weekend.

• Use a Comma and Conjunction: Connect the clauses with a comma followed by a conjunction (e.g., and, but, or).

Example: She enjoys playing tennis, and she practices every weekend.

• Use a Semicolon: Link related independent clauses with a semicolon.

Example: She enjoys playing tennis; she practices every weekend.

By recognizing where one idea ends and another begins, students can improve the clarity and flow of their writing.

7. Apostrophe Misuse

Understanding Apostrophe Usage

Apostrophes are used for two main purposes: to indicate possession and to form contractions. Despite their straightforward rules, apostrophes are often misused in writing, leading to confusion and grammatical errors.

Common Mistake

One of the most common mistakes with apostrophes is adding them where they aren’t needed, such as in plural forms. Another frequent error is confusing its and it’s:

1. Possessive Apostrophes:

• Correct: The teacher’s book (The book belonging to the teacher).
• Incorrect: The teachers book (missing apostrophe for possession).

2. Contractions:

• Correct: It’s raining (It is raining).
• Incorrect: Its raining (missing apostrophe in contraction).

Additionally, students often mistakenly use apostrophes in plural nouns (e.g., apple’s instead of apples).

How to Avoid

To avoid apostrophe misuse, remember these simple rules:

1. Possession: Use an apostrophe to show that something belongs to someone.

• Singular possessive: Add ’s (e.g., The cat’s toy).
• Plural possessive: Add just an apostrophe after the s for words that are already plural (e.g., The cats’ toys).

2. Contractions: Use an apostrophe to combine words into a shorter form.

• Don’t = Do not, It’s = It is, They’re = They are.

3. Avoid Apostrophes in Plurals: Do not use apostrophes to make a noun plural.

• Correct: She has three dogs.
• Incorrect: She has three dog’s.

By following these guidelines, students can ensure their writing is both correct and professional.

8. Sentence Fragments

Understanding Sentence Fragments

A sentence fragment is an incomplete sentence that lacks the necessary components to stand alone as a complete thought. Typically, a complete sentence must have a subject and a verb, and it should express a complete idea. Sentence fragments often occur when a sentence is missing one of these key elements, making it incomplete and leaving the reader confused.

Common Mistake

Students often write sentence fragments by either omitting the subject, verb, or failing to complete the thought. For example:

• Incorrect: Running through the park.
• Correct: She was running through the park.

In the incorrect example, “Running through the park” is a fragment because it does not tell us who is doing the running. The corrected version includes the subject “She” and forms a complete sentence.

How to Avoid

To avoid sentence fragments, ensure that every sentence contains both a subject and a verb, and that it expresses a complete thought. Here are a few tips:

• Identify the Subject and Verb: Before finalizing a sentence, check that it has a clear subject and verb.
• Complete the Thought: Make sure the sentence conveys a complete idea. If the sentence leaves the reader wondering “Who?” or “What?”, it’s likely a fragment.
• Read Aloud: Reading sentences aloud can help you catch fragments that don’t sound complete.

By focusing on creating full, clear sentences, students can avoid the pitfall of writing fragments.

9. Incorrect Word Usage

Understanding Incorrect Word Usage

Using the wrong word in a sentence can completely change its meaning or make the sentence nonsensical. This often happens with words that sound similar (homophones) or with words that have similar meanings but are used in different contexts (e.g., “affect” vs. “effect”).

Common Mistake

One of the most common mistakes is confusing words like “affect” and “effect.” Although they sound similar, they have different meanings:

• Affect is a verb meaning to influence something (e.g., The weather can affect your mood).
• Effect is a noun meaning the result of a change (e.g., The effect of the new policy was immediate).

Students frequently misuse these words, leading to sentences that convey the wrong meaning or confuse the reader.

How to Avoid

To avoid incorrect word usage, students should:

• Keep a List of Commonly Confused Words: Maintaining a list of words that are often mixed up can help students quickly reference the correct usage.
• Understand the Context: Before using a word, consider its meaning and whether it fits the context of the sentence.
• Double-Check Meaning: When in doubt, look up the word to ensure it is being used correctly.

By taking these steps, students can improve their word choice and make their writing clearer and more precise.

10. Passive Voice Overuse

Understanding Active vs. Passive Voice

In English grammar, the voice of a sentence determines whether the subject is performing the action or receiving it. In an active voice sentence, the subject performs the action (e.g., The dog chased the ball). In a passive voice sentence, the subject receives the action (e.g., The ball was chased by the dog).

Why Active Voice is Preferred

Active voice is generally preferred in academic writing because it is more direct, clear, and engaging. It places emphasis on the subject and the action, making sentences stronger and more concise. On the other hand, passive voice can make writing feel indirect or vague, which can detract from the clarity and impact of your argument.

Common Mistake

Many students default to using the passive voice, often without realizing it. This tendency can make their writing less dynamic and harder to follow. For example:

Passive: The experiment was conducted by the students.

Active: The students conducted the experiment.

In the active version, the sentence is clearer and more direct, making it easier for the reader to understand who is performing the action.

How to Avoid

To avoid overusing the passive voice, students should:

• Identify the Subject and Action: Ensure that the subject of the sentence is the one performing the action.
• Revise for Clarity: If a sentence feels awkward or unclear, check to see if it can be rewritten in the active voice.
• Use Grammar Tools: Utilize grammar-checking tools that can highlight passive voice and suggest active alternatives.

By consciously choosing active voice whenever possible, students can make their writing more engaging and effective.

Conclusion

Recap the Importance

Avoiding common grammar mistakes is crucial not only for academic success but also for developing strong communication skills that will serve students throughout their lives. Good grammar ensures clarity, professionalism, and credibility in both academic and professional settings.

Encouragement to Use Tools

Students have access to a variety of tools and resources that can help them improve their writing. From grammar-checking software to educational websites, these tools can provide real-time feedback and guidance, making it easier to avoid mistakes and refine writing skills.

Final Thought

Mastering grammar is an essential step toward becoming a more confident and effective communicator. By taking the time to learn and apply these rules, students can enhance the quality of their writing and express their ideas with greater precision and impact. With consistent practice and the right resources, anyone can achieve clear, compelling, and grammatically correct writing.