‘Complaint’ vs ‘Complain’: Unveiling the Distinct Differences helps learners use each word correctly in English Grammar, writing, and communication.
Learners often get confused because complaint and complaint look similar and sound alike, but they have different grammatical roles. A complaint is a noun that refers to an expression of discontent, pain, grief, unhappiness, discomfort, unease, or dissatisfaction about a product or service issue.
In contrast, complain is a verb describing the action of expressing discomfort, dissatisfaction, or unhappiness. Understanding this distinction makes communication clearer in emails, reviews, conversations, workplace messages, academic reports, customer service messages, and everyday talk.
Quick Answer: Complaint vs. Complain
Complaint is a noun that refers to an expression of dissatisfaction, a problem being protested, or, in some contexts, a physical ailment or formal legal allegation.
Complaint is a verb that means to express dissatisfaction, pain, or discontent. It can also mean to make a formal accusation in certain legal or formal contexts.
| Word | Part of Speech | Meaning | Example |
| Complaint | Noun | An expression or cause of dissatisfaction | I filed a complaint. |
| Complain | Verb | To express dissatisfaction | I complained about the service. |
The easiest rule to remember is:
You complain, but you make a complaint.
For example:
- Correct: I want to complain about the service.
- Correct: I want to make a complaint about the service.
- Incorrect: I want to complain about the service.
- Incorrect: I want to make a complaint about the service.
What Does “Complaint” Mean?
Complaint is a noun. It generally refers to an expression of dissatisfaction, pain, or discontent. It can also refer to the thing causing the dissatisfaction.
For example, if a customer tells a restaurant manager that the food arrived cold, that statement can be called a complaint. The noun describes the expression or issue rather than the action of speaking.
Consider these examples:
- The customer made a complaint about the cold food.
- Her main complaint was the long waiting time.
- The company received several complaints about its billing system.
- Noise was the neighborhood’s biggest complaint.
Merriam-Webster gives several related meanings. Besides an expression of dissatisfaction, it can refer to a cause of protest, a bodily ailment, and specific legal documents.
Complaint as a Noun
A useful test is to place an article or determiner before the word.
You can say:
- a complaint
- the complaint
- my complaint
- your complaint
- several complaints
- their complaints
These structures work because complaint functions as a noun.
You can’t normally say:
- a complain
- the complain
- my complain
Those forms don’t work when you intend the ordinary verb to complain.
Complaint in Different Contexts
The meaning of complaint can shift slightly depending on the situation.
Everyday use:
My main complaint is the price.
Customer service:
The company investigated the customer’s complaint.
Medical use:
The patient’s chief complaint was persistent headaches.
Legal use:
The plaintiff filed a complaint against the defendant.
In medical English, complaint can refer to a bodily ailment or symptom. In legal English, it can refer to a formal pleading that begins a lawsuit or another formal allegation.
What Does “Complain” Mean?
Complaint is a verb. It describes the action of expressing dissatisfaction, pain, or discontent.
For example:
- Customers complain about slow service.
- She complained about the noise.
- He complained to the manager.
- They complained that the room was too cold.
Cambridge defines complaining as saying that something is wrong or unsatisfactory. It also recognizes patterns such as complain about, complain to, and complain that.
Merriam-Webster similarly defines complaint as expressing grief, pain, or discontent. It also records a formal sense involving an accusation or charge.
Forms of “Complain”
Because complaint is a verb, it changes according to tense and grammatical structure.
| Verb Form | Example |
| complain | I complain when something is seriously wrong. |
| complains | She complains about the noise. |
| complained | He complained yesterday. |
| complaining | They are complaining again. |
The past tense isn’t a complaint. It’s a complaint.
That’s an especially important distinction:
- Present: I complain about the service.
- Past: I complained about the service.
- Present continuous: I am complaining about the service.
- Noun: I made a complaint about the service.
Merriam-Webster lists complained, complaining, and complains among the forms of the verb.
Complaint vs. Complain: The Main Grammar Difference
The central difference between complaint vs. complain is simple:
Complaint = noun
Complain = verb
A noun names something. A verb expresses an action, state, or occurrence.
Compare these sentences:
I made a complaint.
I complained.
The first sentence names the complaint as a thing or expression. The second describes the action.
Here’s another comparison:
| Noun Structure | Verb Structure |
| I made a complaint. | I complained. |
| She filed a complaint. | She complained to the manager. |
| We received a complaint. | We complained about the delay. |
| His complaint concerned the price. | He complained that the price was too high. |
The words are related in meaning, but you can’t simply swap them.
That’s where many grammar mistakes begin.
When to Use “Complaint”
Use complaint when the sentence needs a noun.
Several common expressions make this especially clear.
Make a Complaint
Making a complaint is a standard expression.
- I want to make a complaint about the service.
- She decided to make a formal complaint.
- The customer made a complaint about the damaged product.
The verb make takes the noun complaint in this construction.
Cambridge specifically identifies making a complaint as a common collocation.
File a Complaint
File a complaint often sounds more formal.
- The employee filed a complaint with HR.
- The customer filed a complaint against the company.
- She filed a formal complaint with the appropriate department.
This expression works especially well when someone submits a complaint through an official process.
Lodge a Complaint
Lodge a complaint is another established expression, particularly in formal contexts.
- The resident lodged a complaint about the noise.
- She lodged a complaint with the department.
- The customer lodged a formal complaint.
Cambridge notes lodge and file alongside make as established ways to describe submitting a complaint.
Receive a Complaint
Organizations often receive complaints.
- The hotel received several complaints.
- Customer service received a complaint about the order.
- The school received two formal complaints.
Here, complaint clearly acts as the noun because it follows the verb received as the thing being received.
When to Use “Complain”
Use complain when the sentence needs a verb.
Complain About Something
Use complain when you identify the subject of dissatisfaction.
- We complained about the poor service.
- She complained about the noise.
- Customers complained about the high prices.
- He complained about having to work late.
This is one of the most common patterns with complaints. Cambridge gives numerous examples of complaints in everyday and business English.
Complain to Someone
Use complain when you identify the person or organization receiving the complaint.
- I complained to the manager.
- She complained to customer service.
- They complained to the landlord.
- The residents complained to the authorities.
Notice the difference:
complain about the problem
versus
complain to the manager
The first identifies the subject of the complaint. The second identifies the person being addressed.
You can combine both:
She complained to the manager about the slow service.
That’s perfectly natural.
Complain That + Clause
You can also use complain “ before a complete clause.
- He complained that the room was too small.
- She complained that nobody had contacted her.
- The workers complained that the schedule was unfair.
This structure lets you state the specific issue directly.
Complain of
Complaint has a more specialized feel and frequently appears in medical contexts.
- The patient complained of severe headaches.
- She complained of chest pain.
- The child complained of stomach pain.
Cambridge recognizes complaints for describing a physical condition or symptom.4
Read More:Bunk vs. Debunk – Difference, Meaning & Examples
Common Mistakes With Complaint and Complain
The easiest way to master these words is to see the errors people actually make.
| Incorrect | Correct | Explanation |
| I want to complain. | I want to complain. | After to, use the base verb. |
| She made a complaint. | She made a complaint. | A requires a noun here. |
| He filed a complaint. | He filed a complaint. | Field takes a noun. |
| They complain every day. | They complain every day. | The sentence needs a verb. |
| She complained yesterday. | She complained yesterday. | The past tense is complained. |
| We received several complaints. | We received several complaints. | The plural noun is complaints. |
Cambridge even uses the incorrect form “I want to complain” to contrast it with the correct “I want to complain.”
Why “I Want to Complaint” Is Wrong
After to in a construction such as want to, English normally uses the base form of the verb.
Therefore:
- want to complain ✅
- need to complain ✅
- decided to complain ✅
- plan to complain ✅
- want to complaint ❌
Complaint vs. Complain in Customer Service
Customer service provides one of the clearest ways to understand this distinction.
Imagine that you order a laptop online and it arrives damaged.
You might complain to the company’s customer service department:
I complained to customer service about the damaged laptop.
The company might then record your complaint:
Customer service received a complaint about a damaged laptop.
The underlying event remains the same. The grammar changes because you’re describing two different things.
| Situation | Natural Sentence |
| Expressing dissatisfaction | I complained about the order. |
| Addressing customer service | I complained to customer service. |
| Submitting a formal grievance | I filed a complaint. |
| Referring to the documented issue | The company reviewed my complaint. |
| Describing several issues | The company received several complaints. |
This distinction becomes particularly useful in professional writing because complaint often refers to something documented, while complaint describes someone’s action.
Complaint vs. Complain in Business English
Professional communication frequently uses both words, but the choice depends on the sentence.
Common Business Expressions With “Complaint”
- customer complaint
- formal complaint
- written complaint
- official complaint
- complaint procedure
- complaint department
- complaint investigation
- complaint resolution
- complaint handling
Examples:
The company has a formal complaint procedure.
The manager reviewed the customer’s complaint.
Common Business Expressions With “Complain”
- complain about working conditions
- complain about poor service
- complain to management
- complain to customer support
- complain that a policy is unfair
For instance:
Several employees complained about the new schedule.
You could then write:
Management reviewed their complaints.
The first sentence focuses on the action. The second focuses on the issues or statements resulting from that action.
Complaint vs. Complain in Legal and Medical English
These words have meanings beyond everyday customer dissatisfaction.
Legal Meaning of Complaint
In legal contexts, a complaint can have a technical meaning. In U.S. civil procedure, it can refer to the initial pleading in which a plaintiff sets out allegations against a defendant and seeks relief. Merriam-Webster also records a criminal-law sense involving a formal document that sets out an alleged offense and begins proceedings in certain courts.
For example:
The plaintiff filed a complaint against the defendant.
Here, complaining doesn’t simply mean someone saying, “I’m unhappy.” It’s a specific legal document.
Medical Meaning of Complaint
Medical professionals also use complaints in a specialized way.
The patient’s chief complaint was persistent abdominal pain.
In this context, the word refers to the patient’s main symptom, condition, or reason for seeking care.
You can also use the verb:
The patient complained of persistent abdominal pain.
Both sentences describe the same general situation, but their grammatical structures differ.
Merriam-Webster identifies complaint as a noun for a bodily ailment or disease and complain as a verb used when someone speaks about an illness or symptom.
Common Collocations With “Complaint”
A collocation is a combination of words that naturally occur together. Learning these combinations can make your English sound much more natural.
Verbs Used With Complaint
- make a complaint
- file a complaint
- lodge a complaint
- submit a complaint
- receive a complaint
- investigate a complaint
- address a complaint
- resolve a complaint
- withdraw a complaint
For example:
The company promised to investigate the complaint.
Adjectives Used With Complaint
- formal complaint
- official complaint
- written complaint
- customer complaint
- serious complaint
- valid complaint
- legitimate complaint
These combinations are especially useful in workplace, customer service, administrative, and legal writing.
Common Collocations With “Complain”
The verb complain has its own common patterns.
Complain About
- complain about the price
- complain about the noise
- complain about the service
- complain about the weather
- complain about working conditions
Complain To
- complain to the manager
- complain to customer service
- complain to the landlord
- complain to the authorities
- complain to your supervisor
Complain That
- complain that the price is too high
- complain that the service is slow
- complain that the policy is unfair
- complain that the room is uncomfortable
Knowing these patterns is often more useful than memorizing the dictionary definition alone.
Complaint vs. Complain vs. Complained vs. Complaints
These four forms can cause confusion because they look similar.
| Word | Function | Example |
| complain | Base verb | I complain when necessary. |
| complains | Present-tense verb | She complains about everything. |
| complained | Past tense/past participle | They complained yesterday. |
| complaints | Plural noun | We received five complaints. |
One important point deserves extra attention: complaint is not the past tense of complain.
The correct progression is:
complain → complained → complained
Not:
complain → complaint
For example:
She complained about the noise yesterday.
Not:
She complained about the noise yesterday.
Meanwhile, complaint remains a noun:
Her complaint concerned the noise.
A Practical Case Study: One Problem, Different Grammar
Consider a customer named Maya who receives the wrong product.
First, she contacts the company:
Maya complains to customer service about the wrong item.
The customer service representative creates a record:
The company logs Maya’s complaint.
Later, the manager reviews the case:
The manager investigates the complaint.
Finally, the company responds:
Maya complained that the replacement process was too slow.
Notice how the same situation produces different forms.
- complains = Maya’s action
- complaint = the documented issue
- investigates the complaint = the company examines the issue
- complained that = Maya expressed dissatisfaction about a specific matter
This is the heart of complaint vs. complain.
How to Remember the Difference
You don’t need a complicated grammar trick.
Use the Action-or-Thing Test
Ask yourself:
Am I describing the action?
Use complain.
I need to complain.
Am I naming the issue, statement, or grievance?
Use complaints.
I have a complaint.
Use the Article Test
If the sentence naturally needs a, the, my, your, or several, you’re probably looking for the noun complaint.
- a complaint
- the complaint
- my complaint
- your complaint
- several complaints
Remember the Pair
Keep this pair in mind:
Complain = do
Complaint = thing
You complain about a problem. You make or file a complaint about that problem.
It’s a small distinction with a surprisingly large payoff.
Complaint vs. Complain: Real-Life Examples
At a Restaurant
I complained about the cold food.
I made a complaint about the service.
At Work
Several employees complained about the new schedule.
HR received several complaints.
At School
Parents complained to the principal.
The principal reviewed their complaints.
With Online Shopping
The customer complained about the damaged package.
The company investigated the customer’s complaint.
In a Medical Setting
The patient complained of severe headaches.
Headaches were the patient’s chief complaint.
These examples show that the words aren’t competitors in the same grammatical slot. They usually work together.
Quick Rules for Using Complaint and Complain Correctly
Keep these rules handy when you’re writing:
- Complaint is a noun.
- Complaint is a verb.
- Say a complaint, not a complaint.
- Say to complain, not to complain.
- The past tense of complain is complained.
- The plural noun is complaints.
- Use complain about the subject of dissatisfaction.
- Use complaints for the person or organization being addressed.
- Use complain before a complete clause.
- Use complain of when describing a physical symptom, especially in medical contexts.
- Use make a complaint when you need a noun.
- Use file a complaint for a formal submission.
- Use lodge a complaint in formal contexts.
Complaint vs. Complain: Final Verdict
The difference between complaint vs. complaint comes down to grammar and function. Complaint is a noun. It can refer to an expression of dissatisfaction, the issue causing dissatisfaction, a medical ailment, or a formal legal document. Complain is a verb that describes the act of expressing dissatisfaction, pain, or discontent.
When you’re unsure, look at the words around it. If you need an action, choose to complain: I want to complain about the service. If you need a thing or documented grievance, choose a complaint: I want to make a complaint about the service. Once that simple noun-versus-verb distinction becomes familiar, expressions such as complain about, complain to, make a complaint, and file a complaint become much easier to use correctly.
FAQs
1. What is the difference between “complaint” and “complain”?
Complaint is a noun that refers to an expression of dissatisfaction, discomfort, pain, or unhappiness. Complain is a verb that describes the action of expressing dissatisfaction or discomfort.
2. Is “complaint” a noun or a verb?
Complaint is a noun. It names an issue, grievance, or expression of dissatisfaction.
3. Is “complain” a noun or a verb?
Complaint is a verb. It describes the action of expressing dissatisfaction, discomfort, or unhappiness.
4. Which is correct: “the patient complains of” or “the patient complaints of”?
The correct expression is “the patient complains of.” Here, complains is the verb describing what the patient does.
5. Which is correct: “patient complains of pain” or “patient complaints of pain”?
The correct phrase is “patient complains of pain.” The word complains functions as a verb, while pain is the thing being described.
6. What is the plural of “complaint”?
The plural form is “complaints.” For example, “The company received several complaints from customers.”
7. What does “complains” mean?
Complains is the third-person singular form of complaint. It means that someone expresses dissatisfaction, discomfort, or unhappiness.
8. How can I remember “complaint” vs. “complain”?
A useful memory trick is that complaints have a T because complaints are things, or nouns. Complains describe an action, so it is a verb.
9. Can “complaint” be used in formal writing?
Yes. Complaint is common in formal emails, legal documents, workplace communication, customer service, medical reports, and official contexts.
10. What are some synonyms for “complain” and “complaint”?
Synonyms related to complaint include lament, whine, and gripe. Related words for complaint include grievance, discontent, dissatisfaction, and lamentation.
Conclusion
Understanding “Complaint” vs “Complain” becomes easier when you focus on their grammatical roles. Complaint is a noun used for an expression of dissatisfaction, discomfort, pain, grief, or unease, while complaint is a verb describing the action of expressing those feelings. Remembering the simple T = thing rule can help you distinguish complaints from complaints and avoid common spelling and grammar mistakes.
With regular practice, these words become much easier to use naturally. Whether you’re writing emails, reviews, workplace messages, academic reports, medical documents, or everyday conversations, choosing the correct form improves clarity, accuracy, tone, and communication. Once you understand the difference between the noun and verb forms, you can confidently use complaint, complaints, complaints, and complaints in the right contexts.
