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A2 adjective #431 most common 12 min read

certain

Top 431

Practice it Examples Notes & Tips certain in 30 Seconds

Explanation certain in your Level:

At the A1 level, 'certain' is a word you might not use very often, but it is important to understand when you hear it. It mostly means 'sure.' If someone asks you, 'Are you sure?', you can answer, 'Yes, I am certain.' It is a very strong way to say 'yes.' You might also see it in simple signs or instructions, like 'Make certain the door is closed.' At this level, you should focus on the feeling of being 100% sure. Think of it as a step above 'I think.' When you say 'I think it is raining,' you are not sure. When you say 'I am certain it is raining,' you know it is true because you can see the water. It is a helpful word for being very clear with your friends and teachers. You don't need to worry about the more complex meanings yet; just focus on using it to show you are very confident about an answer or a fact. For example, in a classroom, if a teacher asks what 2 + 2 is, you can say, 'I am certain it is 4.' This shows you are a confident learner who knows the basic facts well.

At the A2 level, you begin to use 'certain' in two main ways. First, you use it to show you are sure about something, often using the pattern 'I am certain that...' For example, 'I am certain that the bus stops here.' Second, you start to see 'certain' used before a noun to mean 'some' or 'specific.' You might hear 'Certain animals live in the jungle.' This means not all animals, but some specific ones like lions or monkeys. This is a very useful way to talk about groups of things without having to name every single one. You will also learn the phrase 'make certain,' which means to check something carefully. For example, 'Make certain you have your passport.' This is a common instruction you might hear at an airport or a hotel. At this level, you are building the foundation for more complex sentences. You are moving beyond simple 'yes' and 'no' to express different levels of confidence and to describe groups of things more accurately. It's a great word to help you sound more natural and precise in your daily English conversations.

At the B1 level, you should be comfortable using 'certain' in more varied sentence structures. You will use it to express probability and to talk about things that are likely to happen. For example, 'It is certain to rain this afternoon.' This shows you understand how to use the word to describe the future. You will also start using phrases like 'to a certain extent' or 'to a certain degree.' These are very important for having balanced discussions. If someone asks if you like a movie, you can say, 'To a certain extent, yes, but the ending was a bit slow.' This shows you can see both sides of an issue. You will also encounter 'certain' in more formal reading materials, like news articles or textbooks. You'll notice it being used to refer to unnamed sources or specific conditions. For instance, 'Under certain circumstances, the rules may change.' This level of English requires you to be more nuanced, and 'certain' is a key tool for that. It helps you move away from black-and-white thinking and allows you to express more complex ideas about truth, probability, and specificity.

At the B2 level, 'certain' becomes a tool for professional and academic communication. You will use it to create an authoritative tone in your writing. Instead of saying 'I am sure,' you might write 'It is certain that...' to sound more objective. You will also use 'certain' to handle sensitive information. For example, in a business report, you might write 'Certain employees have expressed concerns,' which allows you to report feedback without naming names. You should also be familiar with idiomatic uses, such as 'a certain something' (an indefinable quality) or 'for certain' (definitely). At this level, you are expected to understand the subtle difference between 'certain' and its synonyms like 'definite' or 'particular.' You will use 'certain' to set boundaries in your arguments, using phrases like 'while certain aspects are clear, others remain debated.' This shows a high level of linguistic control. You are no longer just using the word to mean 'sure'; you are using it to manage information, express complex probabilities, and maintain a professional register in both speaking and writing.

At the C1 level, you use 'certain' with a high degree of sophistication and precision. You understand its role in rhetoric and how it can be used to emphasize a point or to introduce a subtle qualification. You might use it to describe abstract concepts, such as 'a certain malaise' or 'a certain aesthetic.' In academic or legal writing, you use 'certain' to define the scope of a study or a legal principle with absolute clarity. For example, 'The law applies only to certain categories of property.' You are also aware of the historical and etymological weight of the word, recognizing its connection to 'certify' and 'ascertain.' You can use it to navigate complex social situations, where 'a certain' can be used to imply shared knowledge between you and the listener that is kept from others. Your use of the word is effortless, and you can switch between its different meanings—conviction, specificity, and probability—without any hesitation. You use it to add texture and nuance to your language, making your communication not just clear, but also stylistically rich and intellectually engaging.

At the C2 level, your mastery of 'certain' is complete. You use it with the nuance of a native speaker, often employing it in literary or highly specialized contexts. You might use it to discuss philosophical certainty, contrasting it with doubt or existential ambiguity. You are comfortable with all its idiomatic and archaic forms, and you can use it to create specific rhetorical effects. For example, you might use 'a certain' to introduce a character in a way that immediately establishes a specific tone or social class. You understand how the word functions in different registers, from the highly formal language of a supreme court ruling to the subtle, coded language of high-society gossip. You can use 'certain' to qualify your statements with extreme precision, ensuring that every sentence you speak or write conveys exactly the intended level of confidence and specificity. At this level, 'certain' is not just a vocabulary word; it is a versatile instrument that you play with skill to achieve a wide range of communicative goals, from the most practical to the most abstract and artistic.

Practice it Examples Notes & Tips

certain in 30 Seconds

Certain means being completely sure and having no doubts about a fact or an outcome.
It can also mean specific or particular when referring to things or people without naming them.
Common phrases include 'make certain' (to check) and 'to a certain extent' (partly).
It is more formal than the word 'sure' and is often used in professional or academic writing.

The word certain is a versatile adjective in the English language that primarily serves two distinct purposes. At its most common level, it describes a state of being completely sure or confident about something. When you are certain, there is no room for doubt in your mind; you believe the information to be an absolute fact. This is why it is often used in situations involving evidence, strong personal beliefs, or predictable outcomes. For example, a scientist might be certain about a result after many tests, or a child might be certain that their birthday is tomorrow. It conveys a sense of finality and security that words like 'think' or 'hope' do not provide.

The State of Conviction: This refers to the internal feeling of being 100% sure. It is often followed by 'that' or 'of'.

I am certain that I locked the front door before we left the house.

The second major use of certain is to refer to a specific person, thing, or group that the speaker knows but does not want to name directly or does not need to define precisely. This is often seen in the phrase 'a certain' followed by a noun. In this context, it doesn't mean 'sure'; it means 'particular' or 'specific.' For instance, if a teacher says, 'A certain student has not finished their homework,' they are thinking of one specific person but choosing to remain vague for the sake of privacy or politeness. This usage is very common in storytelling and formal writing where the identity of the subject is less important than the action they are performing.

The Determinative Use: Used to single out a specific member of a group without providing their full identity.

There are certain rules that everyone must follow in the library.

In professional settings, 'certain' is used to provide boundaries. Phrases like 'to a certain extent' allow a speaker to agree with a point partially while maintaining their own perspective. This makes the word a powerful tool for negotiation and nuanced discussion. It allows for precision without requiring exhaustive detail. Furthermore, in legal or academic contexts, 'certain' implies a level of evidence that is beyond reasonable doubt. If a fact is described as 'certain,' it is treated as a foundation upon which further arguments can be built. Understanding these layers of meaning helps learners transition from basic communication to more sophisticated, adult-level English usage.

Probability and Fate: Used to describe events that are inevitable or guaranteed to happen.

It is almost certain that the company will expand next year.

Please make certain that all the windows are closed.

He has a certain charm that makes people trust him immediately.

Using 'certain' correctly depends heavily on its position in the sentence and the preposition that follows it. When you want to express your own confidence, the most common structure is 'Subject + be + certain + (that) + clause' or 'Subject + be + certain + of + noun.' For example, 'I am certain that we will win' or 'She is certain of her success.' In these cases, 'certain' acts as a predicative adjective, describing the subject's state of mind. It is important to note that 'certain' is stronger than 'sure.' While 'sure' can sometimes be used casually to mean 'yes,' 'certain' almost always implies a deep, unshakeable conviction.

Predicative Structure: Subject + Verb (be/feel) + Certain. Used to show the speaker's confidence level.

The detectives are certain they have found the right suspect.

When 'certain' is used before a noun, it functions as a determiner or an attributive adjective. In this position, it usually identifies a specific subset of a larger group. For example, 'Certain plants need more water than others.' Here, 'certain' tells the reader that we are not talking about all plants, but a specific, though unnamed, group. This is a very useful way to make generalizations that are still technically accurate. If you said 'Plants need more water,' it might be false for cacti. By adding 'certain,' you make your statement logically sound. This structure is 'Certain + plural noun' or 'A certain + singular noun.'

Attributive Structure: Certain + Noun. Used to specify a particular item or group without naming it.

There is a certain level of risk involved in every new business venture.

Another sophisticated way to use 'certain' is in the phrase 'It is certain that...' This is an impersonal construction that focuses on the fact itself rather than the person who believes it. It is very common in academic writing, journalism, and formal reports. For example, 'It is certain that climate change is affecting sea levels.' This sounds more objective and authoritative than saying 'I am certain that...' because it suggests that the certainty comes from the evidence available to everyone, not just one person's opinion. This structure helps you sound more professional and unbiased in your writing.

Impersonal Construction: It + is + certain + that-clause. Used for stating objective truths or high probabilities.

It is certain that the team will need more funding to finish the project.

Under certain conditions, this chemical reaction can be quite dangerous.

You will encounter the word 'certain' in a wide variety of contexts, ranging from the most formal legal proceedings to casual daily conversations. In the news and media, 'certain' is frequently used to report on events that are highly likely to happen or to describe specific groups of people involved in a story without naming them to protect their identity. For example, a news anchor might say, 'Certain sources within the government have confirmed the report.' This allows the journalist to provide information while maintaining the confidentiality of their informants. In this way, 'certain' acts as a shield for privacy while still providing enough detail to be informative.

Journalistic Anonymity: Using 'certain' to refer to sources or individuals whose names are being withheld.

A certain government official suggested that the policy might change soon.

In the workplace, 'certain' is a key word for clarity and accountability. Managers use it to set expectations and verify tasks. You will often hear the phrase 'make certain' in instructions. For instance, 'Please make certain that the client receives the contract by 5 PM.' This is a polite but firm way of saying 'ensure' or 'double-check.' It emphasizes the importance of the task. Additionally, in meetings, you might hear people use 'certain' to limit the scope of a discussion, such as 'We are only focusing on certain aspects of the budget today.' This helps keep the conversation on track and prevents it from becoming too broad or unmanageable.

Workplace Accountability: Using 'make certain' to emphasize the necessity of verifying a task's completion.

I need to make certain that everyone has the login details for the meeting.

In literature and storytelling, 'certain' is often used to create a sense of mystery or to describe a character's unique quality. An author might write about a character having 'a certain way of walking' or 'a certain look in their eyes.' This usage suggests that the quality is recognizable and distinct, but perhaps difficult to describe in simple words. It invites the reader to use their imagination to fill in the details. This 'ineffable' quality of 'certain' makes it a favorite for poets and novelists who want to evoke a specific mood or atmosphere without being overly literal.

Literary Mystery: Using 'certain' to describe qualities that are distinct but hard to put into words.

She possessed a certain elegance that commanded the room's attention.

To a certain degree, I agree with your assessment of the situation.

One of the most frequent mistakes learners make is confusing 'certain' with 'sure.' While they are often interchangeable, 'certain' is more formal and carries a stronger weight of conviction. You can say 'I'm sure' in response to a casual question like 'Is it raining?', but saying 'I'm certain' in that context might sound a bit too intense or dramatic unless you have actually checked the window. Another common error is the placement of the word. Remember that when 'certain' means 'some' or 'particular,' it must come before the noun. If you say 'The people are certain,' it means the people are confident. If you say 'Certain people,' it means some specific people.

Confusing 'Certain' and 'Sure': Using 'certain' for casual confirmation when 'sure' or 'yes' would be more natural.

Incorrect: Are you certain you want coffee? (Too formal for a simple choice).

Another tricky area is the use of 'a certain' with plural nouns. 'A certain' is strictly for singular nouns, such as 'a certain man' or 'a certain problem.' If you are talking about more than one thing, you must drop the 'a' and just use 'certain,' as in 'certain men' or 'certain problems.' Learners often try to say 'a certain problems,' which is grammatically incorrect. Additionally, be careful with the phrase 'for certain.' It is an adverbial phrase that means 'definitely.' Some learners mistakenly say 'by certain' or 'with certain' when they mean 'for certain.' For example, 'I don't know for certain' is the correct way to express that you lack absolute knowledge.

Singular vs. Plural Usage: Forgetting to remove the article 'a' when using 'certain' with plural nouns.

Correct: I have certain doubts about the plan. (Not 'a certain doubts').

Finally, learners sometimes struggle with the difference between 'certain' and 'specific.' While they are synonyms in some contexts, 'certain' often implies that the identity is known but being withheld, whereas 'specific' implies that the identity is being clearly defined. If you say 'I need a specific tool,' you are describing the type of tool you need. If you say 'I need a certain tool,' it sounds like you have one particular tool in mind that you haven't named yet. Misusing these can lead to subtle misunderstandings about how much information you are actually sharing with your listener. Practice using 'certain' when you want to be slightly vague or when you are expressing absolute, undeniable truth.

The 'Vague' Trap: Using 'certain' when you should be more 'specific' in technical or descriptive writing.

I need certain information before I can finish. (Better: I need specific data points).

It is not certain whether the event will be canceled. (Correct use of probability).

When you want to expand your vocabulary beyond 'certain,' there are several synonyms that can provide more specific meaning depending on the context. If you are talking about being sure, words like 'positive,' 'convinced,' and 'confident' are excellent alternatives. 'Positive' is often used for emphasis, as in 'I am positive I left my keys on the table.' 'Convinced' suggests that you have been persuaded by evidence or logic. 'Confident' is more about your internal feeling of success or ability. Choosing the right one can help you express exactly how sure you are and why.

Sure vs. Certain: 'Sure' is casual and common; 'Certain' is formal and implies absolute proof or lack of doubt.

I am positive that this is the correct path to the summit.

For the meaning of 'specific' or 'particular,' you can use words like 'definite,' 'distinct,' or 'fixed.' 'Definite' is great for plans or times, such as 'We have a definite date for the wedding.' 'Distinct' emphasizes that something is clearly different from others, like 'a distinct smell of smoke.' 'Fixed' is used for things that do not change, like 'a fixed price.' These words help you avoid the slight vagueness that 'certain' can sometimes carry. In academic writing, using 'particular' instead of 'certain' can often make your arguments feel more precise and well-defined.

Particular vs. Certain: 'Particular' focuses on the unique qualities; 'Certain' focuses on the fact that it is one specific item among many.

This particular model of car is known for its fuel efficiency.

On the opposite side, antonyms for 'certain' include 'uncertain,' 'unsure,' 'doubtful,' and 'vague.' 'Uncertain' is the direct opposite and is used for things that are not decided or known. 'Doubtful' suggests that you actually suspect something might be false. 'Vague' is the opposite of the 'specific' meaning of certain; it means something is not clear or well-defined. By understanding these opposites, you can better appreciate the boundaries of the word 'certain' and use it more effectively to create contrast in your writing and speech. For example, 'While the date is certain, the location remains uncertain' is a clear and balanced sentence.

Inevitable vs. Certain: 'Inevitable' describes a future event that must happen; 'Certain' describes the current state of knowledge about that event.

Change is inevitable in a growing organization.

I am convinced that we have made the right decision for the future.

How Formal Is It?

Formal

Neutral

Informal

Child friendly

Slang

Fun Fact

The word 'certain' is related to the word 'secret.' Both come from the Latin 'cernere,' which involves the idea of separating or sifting information to find the truth.

Pronunciation Guide

UK /ˈsɜː.tən/

US /ˈsɝː.tən/

The stress is on the first syllable: CER-tain.

Rhymes With

Curtain Burton Merton Assertin' Divertin' Inert in Alert in Convert in

Common Errors

Pronouncing it as 'cer-tain' with a long 'ai' sound like 'rain'. It should be a short 'un' sound.
Over-pronouncing the 't' in American English, which can sound unnatural.
Confusing the spelling with 'curtain'.
Stressing the second syllable.
Dropping the 'r' sound too much in American English.

Difficulty Rating

Reading 2/5

The word is common in most texts, but its dual meaning can sometimes be confusing for beginners.

Writing 3/5

Using the 'a certain' vs 'certain' plural distinction requires some practice.

Speaking 2/5

Easy to use in place of 'sure,' but the glottal stop in US English can be hard to mimic.

Listening 2/5

Easily recognized, though it can be spoken very quickly in phrases like 'to a certain extent.'

What to Learn Next

Prerequisites

Sure Know Think People Some

Learn Next

Definite Particular Specific Certainty Ascertain

Advanced

Infallible Indubitable Epistemology Certitude Inevitable

Grammar to Know

Adjectives after linking verbs

I feel certain. (Certain describes the subject 'I').

That-clauses as complements

I am certain that he is honest.

Prepositional phrases with 'of'

She is certain of her facts.

Determiners before nouns

Certain students (meaning 'some specific students').

Impersonal 'It' as subject

It is certain that prices will rise.

Examples by Level

I am certain that this is my bag.

I am 100% sure.

Subject + be + certain + that-clause.

Are you certain about the time?

Do you know the exact time without doubt?

Question form: Be + subject + certain + about.

Make certain the cat is inside.

Check to be sure the cat is in the house.

Imperative: Make + certain + (that).

I am not certain of the answer.

I don't know the answer for sure.

Negative: Subject + be + not + certain + of.

He is certain he saw a ghost.

He is very sure he saw something scary.

Subject + be + certain + (that).

Is it certain that we have school today?

Is it a fact that school is open?

Impersonal question: Is + it + certain + that.

We are certain of our team's win.

We are sure our team will win.

Subject + be + certain + of.

She was certain she left her keys here.

She was sure about the location of her keys.

Past tense: Subject + was + certain.

Certain flowers only grow in the spring.

Some specific flowers.

Certain + plural noun.

I am certain that the train leaves at ten.

I know the schedule perfectly.

Be + certain + that-clause.

A certain boy in my class is very funny.

One specific boy (I'm not saying his name).

A + certain + singular noun.

You must make certain that you bring your ID.

You must check and be sure.

Modal verb + make + certain.

Certain parts of the city are very old.

Some specific areas.

Certain + plural noun.

I feel certain that we will have a good time.

I have a strong feeling of confidence.

Feel + certain + that-clause.

There are certain rules for the game.

There are specific rules to follow.

There are + certain + plural noun.

He is certain about his choice of career.

He knows what job he wants to do.

Be + certain + about.

To a certain extent, I agree with you.

I partly agree.

Prepositional phrase: To a certain extent.

It is almost certain that the price will go up.

It is very likely.

It + is + adverb + certain + that.

Under certain conditions, the experiment works.

Only if specific things happen.

Under + certain + conditions.

I don't know for certain if she is coming.

I am not 100% sure.

Adverbial phrase: For certain.

A certain amount of stress is normal.

A specific, limited quantity.

A + certain + amount + of.

Certain people prefer to work alone.

Some specific individuals.

Certain + plural noun.

She has a certain way of making people feel welcome.

A specific, special quality.

A + certain + way + of + gerund.

It is by no means certain that he will win.

It is definitely not sure.

Negative phrase: By no means certain.

The success of the project is by no means certain.

Success is not guaranteed.

Subject + be + by no means + certain.

There is a certain irony in his situation.

A specific type of irony.

There is + a + certain + noun.

Certain aspects of the law are difficult to interpret.

Specific parts of the legal code.

Certain + plural noun.

I am reasonably certain that we can meet the deadline.

I am fairly sure.

Adverb + certain + that-clause.

He felt a certain pride in his daughter's achievement.

A specific feeling of pride.

Verb + a + certain + noun.

For certain, this is the best meal I've ever had.

Definitely.

For certain used as an adverbial opener.

The treaty applies only to certain types of trade.

Only specific categories.

Certain + types + of.

It is almost certain to be a sell-out concert.

It is very likely all tickets will be sold.

It + is + adverb + certain + to-infinitive.

There is a certain indefinable quality about her art.

A specific quality that is hard to describe.

A + certain + adjective + noun.

The report highlights certain systemic failures.

Points out specific, deep-rooted problems.

Certain + plural noun.

One cannot be certain of the long-term effects.

It's impossible to know for sure.

One + cannot + be + certain + of.

He spoke with a certain degree of hesitation.

He was a bit hesitant.

A + certain + degree + of.

Certain scholars argue that the text is a forgery.

Some specific experts.

Certain + plural noun (Subject).

It remains to be seen if certain promises will be kept.

We don't know yet if specific promises will be honored.

Passive voice: certain + promises + will be kept.

The company faces certain death if it does not innovate.

Inevitable failure.

Certain + noun (metaphorical).

A certain level of competence is expected from all staff.

A specific required standard.

A + certain + level + of.

The protagonist is haunted by a certain existential dread.

A specific, deep philosophical fear.

A + certain + adjective + noun.

Philosophers have long debated what we can truly know for certain.

What is absolutely, undeniably true.

Know + for certain.

The prose possesses a certain rhythmic cadence.

A specific musical quality in the writing.

Possesses + a + certain + adjective + noun.

Certain nuances of the dialect are lost in translation.

Specific small details of the language.

Certain + plural noun.

He maintained a certain distance from his colleagues.

He kept a specific, intentional gap.

Maintained + a + certain + noun.

The outcome was far from certain until the final vote.

The result was very unsure.

Far from certain.

There is a certain poetic justice in the villain's downfall.

A specific, fitting kind of justice.

A + certain + adjective + noun.

Certain of his convictions were challenged by the new evidence.

Some of his specific beliefs.

Certain + of + possessive + plural noun.

Synonyms

sure positive confident convinced definite unquestionable

Antonyms

uncertain unsure doubtful

Common Collocations

Certain death

Certain age

Certain extent

Certain amount

Feel certain

Make certain

For certain

Fairly certain

Reasonably certain

Almost certain

Common Phrases

To a certain degree

— Partly or in some way. Used to qualify a statement.

To a certain degree, she is right about the costs.

A certain something

— A quality that is noticeable but hard to describe. Often used for charm.

That old house has a certain something that I love.

Of a certain age

— A polite way to refer to someone who is no longer young, usually middle-aged.

He is a gentleman of a certain age.

Under certain circumstances

— Only if specific conditions are met. Used in rules and logic.

Under certain circumstances, you can get a refund.

Make certain of

— To check something so that you are sure about it.

I need to make certain of the flight times.

Certain of success

— Feeling very confident that one will achieve their goal.

The athlete seemed certain of success.

A certain person

— A specific individual who is not being named.

A certain person told me your secret.

In certain cases

— In some specific situations but not all.

In certain cases, the medicine can cause sleepiness.

Certain of one's ground

— To be very sure of one's facts or position in an argument.

The lawyer was certain of his ground.

For sure and certain

— An emphatic way of saying definitely (more common in some dialects).

He'll be there for sure and certain.

Often Confused With

certain vs Curtain

A curtain is a piece of cloth used to cover a window. Certain is an adjective meaning sure.

certain vs Sure

Sure is more casual. Certain is more formal and implies a stronger conviction.

certain vs Specific

Specific means clearly defined. Certain often means specific but unnamed.

Idioms & Expressions

"Certain as death and taxes"

— Something that is absolutely guaranteed to happen. It comes from a famous quote by Benjamin Franklin.

In this business, change is as certain as death and taxes.

Informal/Humorous

"A certain je ne sais quoi"

— A French phrase used in English to describe an appealing quality that cannot be easily named.

The restaurant has a certain je ne sais quoi that keeps people coming back.

Sophisticated

"Know for certain"

— To have absolute knowledge about something without any doubt.

No one knows for certain how the universe began.

Neutral

"To a certain extent"

— Used to say that something is true but only up to a point.

To a certain extent, I agree, but we must consider the risks.

Neutral

"Make double certain"

— To check something twice to be absolutely sure.

I'll make double certain that the gate is locked.

Informal

"Certain of one's facts"

— To be completely sure that the information one has is correct.

Before you accuse him, make sure you are certain of your facts.

Formal

"A certain air"

— A specific manner or appearance that someone has.

He had a certain air of mystery about him.

Literary

"Nothing is certain"

— A philosophical phrase suggesting that life is unpredictable.

In politics, nothing is certain until the votes are counted.

Neutral

"Certain of oneself"

— To be confident in one's own abilities or decisions.

She walked onto the stage looking very certain of herself.

Neutral

"To be certain of a welcome"

— To know that you will be treated kindly when you arrive somewhere.

You are always certain of a welcome at my house.

Polite

Easily Confused

certain vs Sure

They both mean 'without doubt.'

Certain is more formal and stronger. You can use 'sure' as an exclamation ('Sure!'), but not 'certain'.

I am sure it's fine. vs. I am certain of the results.

certain vs Particular

Both can mean 'specific.'

Particular focuses on the unique details of one thing. Certain focuses on the fact that it is one specific item among others.

This particular car is red. vs. A certain car was seen at the scene.

certain vs Definite

Both imply clarity and no doubt.

Definite is usually used for plans, times, or shapes. Certain is used for feelings of conviction or unnamed items.

We have a definite plan. vs. I am certain the plan will work.

certain vs Positive

Both mean 'very sure.'

Positive is often used to describe a person's memory or attitude. Certain is more objective.

I am positive I saw him. vs. It is certain that he was there.

certain vs Some

Both can refer to an indefinite group.

Some is general. Certain implies that the speaker knows exactly which ones they are talking about, even if they don't say.

Some people like tea. vs. Certain people in this room like tea.

Sentence Patterns

I am certain.

I am certain that [clause].

I am certain that he is here.

Certain [plural noun]...

Certain people like spicy food.

To a certain extent...

To a certain extent, you are right.

Make certain that...

Make certain that the door is locked.

It is certain that...

It is certain that the team will win.

A certain [noun] of [noun]...

A certain degree of skill is required.

[Noun] is far from certain.

The outcome is far from certain.

Word Family

Nouns

Verbs

Adjectives

How to Use It

frequency

Very high in both spoken and written English.

Common Mistakes

I am certain of that he is coming. → I am certain that he is coming.
Do not use 'of' before a 'that' clause. Use 'of' with nouns and 'that' with clauses.
A certain people told me. → Certain people told me.
'A certain' is only for singular nouns. For plural, just use 'certain.'
I don't know by certain. → I don't know for certain.
The correct preposition for this adverbial phrase is 'for.'
Are you certain for the time? → Are you certain about the time?
When asking about a specific fact, 'about' is the more natural preposition.
It is very certain to rain. → It is almost certain to rain.
'Almost' is a better modifier for certainty than 'very.'

Tips

Placement Matters

Remember: 'I am certain' (Sure) vs. 'Certain things' (Some). The meaning changes based on where the word is.

Formal Writing

Use 'It is certain that...' to make your writing sound more objective and evidence-based.

Polite Agreement

Say 'Certainly!' instead of 'Okay' to sound more professional and helpful.

Catch the Nuance

When you hear 'a certain person,' the speaker is usually keeping a secret or being polite.

Avoid Redundancy

Try not to use 'very' with 'certain.' Use 'absolutely' or 'completely' if you need more emphasis.

Nuanced Discussion

Use 'to a certain extent' to disagree politely with someone's point.

The 'C' Rule

Certain = Confident. Both start with 'C'. If you are certain, you are confident.

Context Clues

If 'certain' is followed by 'of' or 'that,' it almost always means 'sure.'

Collocations

Memorize 'make certain' and 'for certain' as they often appear in English proficiency tests.

The Soft 'T'

In casual American English, the 't' in 'certain' is often replaced by a small catch in the throat.

Memorize It

Mnemonic

Think of a 'CERT'ificate. A certificate makes something 'CERT'ain or official.

Visual Association

Imagine a giant green checkmark next to the word. The checkmark means 'yes, correct, certain.'

Word Web

Sure Positive Fixed Specific Infallible Definite Particular Clear

Challenge

Try to use 'certain' in three different ways today: once to show you are sure, once to refer to a specific person, and once in the phrase 'make certain.'

Word Origin

The word 'certain' comes from the Old French word 'certain,' which was derived from the Latin word 'certus.' The Latin 'certus' is a variation of 'cernere,' which means 'to distinguish' or 'to decide.'

Original meaning: Originally, it meant 'settled,' 'fixed,' or 'determined.'

It belongs to the Indo-European family, specifically the Italic branch through Latin.

Cultural Context

Be careful when using 'of a certain age' as it can sometimes be seen as patronizing, even though it is intended to be polite.

In the UK, 'certainly' is a very common polite response. In the US, 'sure' is more common, but 'certainly' is used for extra formality.

Benjamin Franklin's quote: 'In this world, nothing can be said to be certain, except death and taxes.' The movie 'A Certain Smile' (1958). The song 'Certain Things' by James Arthur.

Practice in Real Life

Real-World Contexts

Giving Directions

I am certain this is the right way.
Make certain you turn left at the light.
Are you certain we haven't passed it?
It is certain to be on the right side.

Work Meetings

To a certain extent, I agree.
We need to make certain of the budget.
Certain members of the team are away.
It is certain that we need more time.

Shopping

I'm not certain if this fits.
Is it certain that this is on sale?
I'm looking for a certain type of shoe.
Make certain you keep the receipt.

School/Studying

I am certain of my answer.
Certain chapters are harder than others.
Make certain to study for the test.
It is certain that the exam is tomorrow.

Daily Life

I don't know for certain.
A certain person called for you.
I feel certain it will be a good day.
Make certain the stove is off.

Conversation Starters

"Are you certain that you want to move to a new city next year?"

"Do you think there are certain things that everyone should know how to do?"

"Is there a certain movie that you can watch over and over again?"

"Are you certain about your plans for the upcoming weekend?"

"Do you feel certain that technology is making our lives better?"

Journal Prompts

Write about a time when you were absolutely certain about something, but you turned out to be wrong.

Describe a certain place that makes you feel very happy and explain why it is special to you.

What are certain goals you want to achieve in the next five years? How will you make certain you reach them?

Discuss a topic where you agree with the majority only to a certain extent. What are your specific doubts?

Reflect on the phrase 'nothing is certain.' How does this idea affect the way you live your life?

Frequently Asked Questions

10 questions

While people say it in casual speech, it is technically redundant because certainty is absolute. It is better to say 'completely certain' or just 'certain.'

'Certain' is an adjective (I am certain). 'Certainly' is an adverb used for emphasis or to say yes (I will certainly be there).

You don't. Use 'a certain' for singular (a certain man) and just 'certain' for plural (certain men).

Yes, 'certain' is generally considered more formal and is preferred in academic and professional writing.

It means 'partly' or 'up to a point.' It is used when you agree with something but not completely.

Yes, when used before a noun (e.g., certain animals), it means 'some specific' members of a group.

The most direct opposite is 'uncertain.' Other opposites include 'unsure' and 'doubtful.'

It means to check or verify something so that you are sure it is correct or has been done.

Yes, they mean the same thing, but 'for certain' is slightly more formal.

It refers to a special quality that is hard to describe or name, often used to describe someone's charm.