Ten Everyday Grammar Mistakes That Undermine Your Writing

Misused Verbs and Comparatives

1. I should have studied more

This mistake is extremely common, especially in informal writing and speech. The problem lies in the use of “of” instead of the correct helping verb “have.” While “should of” may sound acceptable when spoken quickly, in writing, it is clearly incorrect.

Why the mistake happens:
In spoken English, contractions like “should’ve” often sound like “should of,” leading many to assume that’s how it’s written. But “should’ve” is actually a shortened form of “should have,” not “should of.”

Grammatical breakdown:

• “Should” is a modal verb that needs to be followed by a base verb or a perfect form (with “have”). 
• “Have” is the auxiliary (helping) verb used to form the perfect tense: “should have studied.” 
• “Of” is a preposition, not a verb, and it cannot function as an auxiliary verb. 

Incorrect:
I should of studied more.

Correct:
I should have studied more.

Why it matters:
Using “of” instead of “have” distorts the meaning and makes your writing seem careless. In academic or professional settings, this type of mistake can undermine your credibility.

How to avoid it:
Say the sentence out loud. If you’re thinking of writing “should of,” try substituting the full version—“should have.” It will always be correct in this construction.

Other examples of the same mistake:

• She could of won the race. → She could have won the race. 
• They might of arrived earlier. → They might have arrived earlier. 
• You would of enjoyed the concert. → You would have enjoyed the concert. 

2. I’d rather complete the task with a group then do it by myself

This is a mistake involving a pair of very similar words: “then” and “than.” The incorrect use of “then” instead of “than” changes the meaning of the sentence entirely.

Why the mistake happens:
“Then” and “than” are pronounced very similarly, and in casual conversation, people often use them interchangeably. However, they serve entirely different grammatical functions.

Grammatical breakdown:

• “Then” is used to indicate time or the next step in a sequence. 
• “Than” is used for comparisons. 

In the sentence “I’d rather complete the task with a group then do it by myself,” the intention is to compare two alternatives: completing a task with a group or doing it alone. This is a comparison, so “than” is the correct word.

Incorrect:
I’d rather complete the task with a group then do it by myself.

Correct:
I’d rather complete the task with a group than do it by myself.

Why it matters:
Using “then” in a comparative sentence makes it confusing or nonsensical. It suggests a sequence of actions rather than a choice between two options. This may lead to misinterpretation by the reader.

How to avoid it:
Ask yourself whether the sentence is:

• Comparing two things? Use “than.” 
• Referring to a point in time or what happens next? Use “then.” 

Examples to clarify the difference:

Use of “then”:

• First, we’ll go to the store, then we’ll head to the park. 
• I brushed my teeth, then I went to bed. 

Use of “than”:

• She’s taller than her brother. 
• It’s better to plan ahead than to rush last minute. 

Other incorrect examples:

• He would rather walk then take the bus. → He would rather walk than take the bus. 
• I’d prefer tea then coffee. → I’d prefer tea than coffee. 

Additional Notes for Clarity

These first two mistakes are not just surface-level errors. They highlight a deeper issue with how spoken English influences written English. In speech, tone, body language, and intonation can often mask grammatical mistakes. But when writing, words stand alone. There’s no tone to convey intent, so grammar must do all the work. This makes clarity and correctness essential.

Another important point is that both examples involve decisions or preferences. Modal verbs like “should,” “would,” and “might,” as well as comparative structures like “rather…than,” show how people evaluate choices or actions. These expressions are fundamental to everyday communication, so getting them right improves both writing and speaking skills.

3. How you write effects how others perceive you

This mistake involves the incorrect use of “effects” instead of the verb “affects.” These two words sound similar but function differently in a sentence. Confusing them can drastically change the intended meaning.

Why the mistake happens:
Because “affect” and “effect” are near-homophones and both relate to change or consequence, many people use them interchangeably. This leads to frequent confusion in writing.

Grammatical breakdown:

• Affect is typically a verb meaning to influence or change. 
• Effect is usually a noun meaning the result or outcome of a change. 

In the sentence “How you write effects how others perceive you,” the speaker is trying to say that writing has an impact on perception. Since the intended meaning is to describe an influence, the verb “affects” is required.

Incorrect:
How you write effects how others perceive you.

Correct:
How you write affects how others perceive you.

Why it matters:
Using the wrong word in this context changes the part of speech and the function in the sentence. “Effects” as a noun doesn’t logically fit in the place of a verb. This makes the sentence confusing or grammatically incorrect.

How to avoid it:
A simple mnemonic:

• Affect = Action (both start with “A”) 
• Effect = result 

Correct usage examples:

• Cold weather affects my mood. 
• The new law had a major effect on small businesses. 

Incorrect examples and corrections:

• The noise from the construction really effected my sleep. → Affected 
• What’s the affect of this medication? → Effect 

Exceptions:
Yes, it’s true that both words can occasionally take on the other part of speech:

• Effect as a verb: “The new manager will effect major changes.” 
• Affect as a noun (rare, typically in psychology): “He showed a flat affect.” 

However, these uses are rare in everyday writing. Sticking to affect as a verb and effect as a noun will serve you well most of the time.

4. After all this grammar review, I need to lay down

This error comes from confusion between the verbs “lay” and “lie,” which have different meanings, uses, and forms depending on tense. Though similar sounding, they are not interchangeable.

Why does the mistake happen?
“Lay” and “lie” are often misused because of how they overlap in different tenses. For instance, the past tense of “lie” is “lay,” which looks exactly like the base form of the other verb.

Grammatical breakdown:

• Lie is an intransitive verb, meaning it does not take a direct object. It means to recline or rest. 
• Lay is a transitive verb, meaning it requires a direct object. It means to place something down. 

Present Tense:

• Lie (yourself) 
• Lay (an object) 

Past Tense:

• Lie → lay 
• Lay → laid 

In the sentence “I need to lay down,” there is no direct object receiving the action, which means the verb must be “lie.”

Incorrect:
After all this grammar review, I need to lay down.

Correct:
After all this grammar review, I need to lie down.

Why it matters:
This mistake can confuse the meaning of a sentence, especially in written English where readers rely on grammar to interpret what is happening. Using “lay” without a direct object leads to incorrect syntax and potential misunderstanding.

Examples of correct usage:

Lie – no object needed:

• I lie down every afternoon for a short nap. 
• He lies awake at night thinking about work. 

Lay – requires an object:

• I lay the book on the desk before leaving. 
• Please lay your coat on the chair. 

Past tense examples:

• Yesterday, I lay in bed all day. (past of lie) 
• She laid the baby in the crib. (past of lay) 

Common confusion with past tense:

• Don’t say: “I laid down for a while” (unless you are laying down something else). 
• Correct: “I lay down for a while.” 

How to remember it:
Use a test object. If you can add a noun after the verb (like “a pillow”), then “lay” is likely correct.

• I want to ___ a pillow. → Lay a pillow 
• I want to ___ down. → Lie down 

Informal Contractions, Pronoun Misuse, and Apostrophes

5. You’re kidding me! I’m never gonna remember all this

This sentence contains a very common informal contraction: “gonna.” While this kind of language is widely accepted in speech or casual texting, it’s not appropriate for formal writing or professional communication.

Why the mistake happens:
People often write how they speak. In rapid conversation, “going to” frequently becomes “gonna.” The problem arises when this speech habit carries over into written work, where clarity and correctness matter more.

Grammatical breakdown:

• “Gonna” is a nonstandard contraction of “going to.” It’s not recognized as proper English in formal contexts. 
• “Gonna” = informal speech 
• “Going to” = standard grammar 

Incorrect:
I’m never gonna remember all this.

Correct:
I’m never going to remember all this.

Why it matters:
Using “gonna,” “wanna,” “gotta,” or similar contractions in formal writing can make the text appear lazy or immature. It gives the impression that the writer did not take the task seriously.

Other informal expressions to avoid:

• “Wanna” → want to 
• “Gotta” → have to or got to 
• “Cuz” or “’cause” → because 
• “Lemme” → let me 
• “Ima” → I’m going to 

Correct usage in formal writing:

• I want to attend the meeting. 
• We have to leave early. 
• Let me know what time you’ll arrive. 

Context where informal is okay:
These expressions are perfectly acceptable in dialogue in fiction, personal journaling, or texting between friends. The key is knowing your audience and purpose.

Another point in the sentence:
The word “You’re” is used correctly here. It’s a contraction of “you are.” Had it been spelled “Your,” the sentence would’ve been incorrect.

Incorrect:
Your kidding me!
Correct:
You’re kidding me!

6. This grammar review is making John and I hungry

This mistake involves incorrect pronoun usage, specifically the confusion between “I” and “me.” This error often occurs when people try to sound more formal and end up misusing the subject form of a pronoun where an object is required.

Why does the mistake happen? 

Many people were taught to always say “John and I” instead of “me and John” in order to sound polite or formal. Unfortunately, that advice often leads to “I” being used incorrectly as an object of the verb, when it should be “me.”

Grammatical breakdown:

• “I” is a subject pronoun (used when the person is doing the action). 
• “Me” is an object pronoun (used when the person is receiving the action). 

In the sentence “This grammar review is making John and I hungry,” the pronouns are on the receiving end of the action (being made hungry), so “me” is the correct form.

Test trick:
Remove the other person’s name and test the sentence with just the pronoun.

• Would you say “This grammar review is making I hungry”? No. 
• You’d say “This grammar review is making me hungry.” That confirms “me” is correct. 

Incorrect:
This grammar review is making John and I hungry.

Correct:
This grammar review is making John and me hungry.

Why it matters:
Using “I” in place of “me” creates a jarring effect for readers who are familiar with proper grammar. It signals a misunderstanding of basic sentence structure, even if the intention was to sound proper.

More examples of correct usage:

• She gave the documents to Sam and me. 
• Between you and me, this is confusing. 
• The gift was from Lisa and me. 

When to use “I”:

• John and I went to the library. 
• My friend and I are studying for the test. 

Summary tip:
To decide between “I” and “me,” remove the other subject or object and see what makes sense on its own.

7. Its not okay to misuse apostrophes

This sentence contains one of the most frequent and frustrating grammar mistakes: confusing “its” and “it’s.” These two tiny words are often misused, yet they serve different grammatical roles.

Why the mistake happens:
Most possessive nouns use an apostrophe + s (for example, the dog’s toy, the girl’s book). But with “it,” the possessive is formed differently—without an apostrophe. That inconsistency leads many to assume “it’s” shows possession, when in fact it doesn’t.

Grammatical breakdown:

• “It’s” is a contraction meaning “it is” or “it has.” 
• “It’s” is a possessive pronoun, meaning “belonging to it.” 

In “Its not okay,” the intended meaning is “It is not okay.” Therefore, the contraction “it’s” should be used.

Incorrect:
Its not okay to misuse apostrophes.

Correct:
It’s not okay to misuse apostrophes.

Why it matters:
Using the wrong form of “it’s” or “its” is one of the easiest ways to undermine your credibility as a writer. Even though it’s a simple mistake, readers often interpret it as a sign of sloppy thinking or poor editing.

Test trick:
Try replacing the word with “it is.”

• If it works, use it’s. 
• If not, use its. 

Correct examples:

• It’s raining outside. (It is raining.) 
• The machine lost its power during the storm. 

Incorrect examples and corrections:

• The cat chased it’s tail. → The cat chased its tail. 
• Its a beautiful day. → It’s a beautiful day. 

More apostrophe reminders:

• Apostrophes do not make words plural. 
• Use apostrophes to show possession (the dog’s bone) or to form contractions (don’t, can’t). 

These three grammar points illustrate the fine balance between spoken and written English. Whether you’re using contractions, pronouns, or apostrophes, writing requires a precision that speech often allows you to skip. Mastering these small details leads to clearer, more professional, and more trustworthy communication.

Homophones, Subject-Verb Agreement, and Common Spelling Errors

8. Just because too or more words sound the same doesn’t mean your allowed to use them without knowing there purpose

This sentence is packed with three different homophone errors. These types of mistakes are especially common because the words sound identical when spoken, making it easy to confuse them in writing.

Why the mistake happens:
Homophones are words that sound the same but have different meanings and spellings. Because they’re indistinguishable in speech, many writers rely on sound alone when choosing the spelling, resulting in errors.

Let’s break down the errors in this sentence:

a. “Too or more words”

This phrase should be “two or more words.” The word “two” refers to the number. “Too” means “also” or “excessively.”

Correct:
Just because two or more words sound the same…

b. “Your allowed to use them…”

“Your” is a possessive pronoun, meaning “belonging to you.” In this sentence, the meaning is “you are allowed,” so the contraction “you’re” is correct.

Correct:
…doesn’t mean you’re allowed to use them…

c. “…without knowing there purpose”

“There” refers to a place. The correct word here is “their,” which is the possessive form of “they.” “Their purpose” means the purpose that belongs to them.

Correct:
…without knowing their purpose.

Fully corrected sentence:
Just because two or more words sound the same doesn’t mean you’re allowed to use them without knowing their purpose.

Why it matters:
Mixing up these homophones can make your writing difficult to understand and appear careless, even when the overall message is clear. Readers may have to pause to interpret what you mean, which interrupts the flow of communication.

Common homophone sets to watch for:

• There / They’re / Their 
  • There = location (There is the book.) 
  • They’re = they are (They’re coming soon.) 
  • Their = possession (Their car is outside.) 
• Your / You’re 
  • Your = possession (Your idea is great.) 
  • You’re = you are (You’re welcome.) 
• To / Too / Two 
  • To = preposition (Go to the store.) 
  • Too = also or excessively (I’m coming too. / That’s too loud.) 
  • Two = the number (Two of us are going.) 

How to avoid these mistakes:
When editing, say the sentence aloud and mentally substitute each homophone option to see which one makes logical and grammatical sense. Always double-check the word’s function in the sentence.

9. This review of the rules of grammar have really helped

This sentence demonstrates an issue with subject-verb agreement. At first glance, it might appear fine, but when you isolate the subject and verb, the error becomes obvious.

Why the mistake happens:
Writers often get confused when a singular subject is followed by a modifying phrase with plural nouns. In this case, “review” is the subject, but “rules of grammar” is a modifying phrase that might make the writer think the subject is plural.

Grammatical breakdown:

• Subject: “review” (singular) 
• Verb: “have helped” (plural) 

These don’t agree. The verb should be has helped to match the singular subject.

Incorrect:
This review of the rules of grammar have really helped.

Correct:
This review of the rules of grammar has really helped.

Why it matters:
Subject-verb agreement affects the grammatical structure of a sentence. Errors here make sentences feel off, even if readers can guess the meaning. In formal writing, these small mistakes signal lack of control over sentence construction.

How to find the correct subject:
Strip away prepositional phrases like “of the rules of grammar.” You’re left with:

• “This review… has really helped.” 

Other examples:

• The list of items is on the table. 
• A bouquet of flowers was delivered. 

Even though “items” and “flowers” are plural, they are part of prepositional phrases and not the true subject of the sentence.

More complex examples with multiple subjects:

• Sugar and water are the main ingredients. (Both subjects are plural, so use “are.”) 
• Neither my dad nor my brothers like seafood. (Use the verb that matches the subject closest to it: “brothers.”) 

Key rule:
Make sure the verb matches the true subject, not the closest noun.

10. There are alot more mistakes that could have made the list

This sentence contains a spelling error that’s so common it has almost become invisible to many writers. The problem lies in the use of “alot,” which is not actually a word.

Why the mistake happens:
In casual speech, “a lot” sounds like one word, leading many people to write it that way. However, in standard English, it is always written as two words: “a lot.”

Grammatical breakdown:

• “A lot” = a large quantity or number 
• “Alot” = incorrect spelling (not recognized as a standard word) 

Correct:
There are a lot more mistakes that could have made the list.

Why it matters:
Even though “alot” is widely used online, it’s still incorrect in academic, business, or professional writing. Using the proper spelling signals attention to detail and writing skill.

What about “allot”?
“Allot” is a valid word, but it means to distribute or assign something. It has a completely different meaning from “a lot.”

Examples of correct usage:

• Each speaker is allotted ten minutes. 
• She has a lot of experience in project management. 

How to remember it:
Think of “a lot” as a phrase just like “a bunch” or “a few.” You wouldn’t write “abunch” or “afew,” so don’t write “alot” either.

Final Thoughts

Grammar is more than just a set of rules—it’s a tool that helps us communicate clearly and effectively. While it’s easy to overlook small mistakes, especially in casual settings, consistently using proper grammar strengthens your writing and helps ensure your message is understood as intended. Common errors like confusing “your” and “you’re” or misusing verbs like “lay” and “lie” may seem minor, but they can change the meaning of a sentence or distract the reader. The good news is that mastering grammar doesn’t require perfection—it simply takes awareness and attention to detail. By recognizing and correcting frequent mistakes, you make your writing more polished, professional, and persuasive. Whether you’re sending an email, writing an essay, or posting online, strong grammar gives your words the clarity and credibility they deserve.