Ways to Express Uncertainty in English

Hello, English learners. Welcome to a new lesson. Today, we are going to look at different ways to express uncertainty in English. These expressions will help you show doubt, hesitation, indecision and a lack of confidence more naturally.

There are many ways to express uncertainty in English, depending on the situation and the degree of doubt you want to communicate. Some expressions are common in everyday conversation, while others are more suitable for formal writing, professional discussions and Cambridge speaking exams.

You can also read our lesson on ways to express certainty in English.

Here are the expressions we are going to look at:

• not certain or uncertain
• not sure or unsure
• unconvinced
• have doubts
• doubtful
• dubious
• sceptical
• tentative
• bewildered
• be in two minds
• be inclined to think or believe
• it remains to be seen
• as far as I know
• I cannot say for certain
• there is a possibility that

---

Ways to Express Uncertainty in Everyday English

Not Certain or Uncertain

Meaning: not knowing something definitely or not feeling confident about a decision.

Register: Neutral.

Both not certain and uncertain can describe a lack of knowledge or confidence.

• Scientists are not certain whether life exists elsewhere in the universe.
• Celia did not want to rush into marriage because she was uncertain about her feelings for Greg.

We commonly use these patterns:

• not certain whether
• uncertain about something
• uncertain how, what or where

Not Sure or Unsure

Meaning: not knowing something or not feeling confident about what to do.

Register: Neutral and very common in spoken English.

Not sure is one of the most natural ways to express uncertainty in everyday conversation.

• Could you give me a hand? I’m not sure how to put up this shelf.
• Stephen was unsure how to answer the question.

You can make the phrase sound more cautious by saying:

• I’m not entirely sure.
• I’m not quite sure.
• I’m not absolutely sure.

---

Ways to Express Uncertainty and Doubt

Unconvinced

Meaning: not persuaded that something is true, effective or a good idea.

Register: Neutral to formal.

Being unconvinced does not simply mean that you lack information. It means that you have heard an explanation or argument but still do not fully believe it.

• The jury remained unconvinced that the suspect was innocent.
• The engineer was unconvinced that the project would be cost-effective.

Common patterns include:

• unconvinced that
• unconvinced by something
• remain unconvinced

Have Doubts

Meaning: to feel uncertain or worried about whether something is true, sensible or likely to succeed.

Register: Neutral.

• If you have any doubts about the offer, do not accept it immediately.
• Many residents have doubts about the effectiveness of the new law.

You can describe the strength of your doubts:

• have some doubts
• have serious doubts
• have considerable doubts
• have no doubt

Be careful: have no doubt expresses certainty.

• I have no doubt that she will succeed.

Doubtful

Meaning: unlikely, uncertain or not completely convinced.

Register: Neutral to formal.

Doubtful is often used when we think something is unlikely to happen.

• It seems doubtful that they will repay the money.
• The committee was doubtful about the proposed music festival.

The most natural patterns are:

• It is doubtful that…
• It is doubtful whether…
• be doubtful about something

In everyday English, we often use I doubt instead:

• I doubt they will finish the work today.

Dubious

Meaning: uncertain, suspicious or not convinced that something is honest, reliable or sensible.

Register: Neutral to formal.

Dubious is stronger than simply being unsure. It often suggests that you believe something may be false, unreliable or morally questionable.

• The article was based on information from a dubious source.
• I am dubious about John’s ability to manage the business.

Compare:

• I’m uncertain about the result.
• I’m dubious about the result.

The first sentence means that the result is unknown. The second suggests that the result may not be reliable.

Sceptical

Meaning: having doubts about whether a claim, idea or plan is true or likely to succeed.

Register: Neutral.

Sceptical is the usual British spelling. In American English, it is normally spelt skeptical.

• The doctor was sceptical about the effectiveness of the treatment.
• My wife thinks the cheap air-conditioning unit is a bargain, but I’m rather sceptical.

Common patterns include:

• sceptical about something
• sceptical of something
• sceptical that

Tentative

Meaning: not definite or final; subject to change.

Register: Neutral to formal.

Tentative does not normally describe someone who simply does not know an answer. It is commonly used for plans, agreements, conclusions and arrangements that have not yet been confirmed.

• We have made tentative plans to go skiing in January.
• The board reached a tentative agreement.

Common combinations include:

• tentative plan
• tentative agreement
• tentative date
• tentative conclusion
• tentative suggestion

A person may also speak or act tentatively when they lack confidence.

• She gave a tentative smile and entered the room.

Bewildered

Meaning: extremely confused and unable to understand what is happening.

Register: Neutral.

Bewildered is connected with uncertainty, but its main meaning is confusion.

• When nobody met him at the airport, Dean felt completely bewildered.
• The number of complicated instructions left me bewildered.

Related words include:

• bewildering – causing confusion
• bewilderment – a state of confusion

---

Ways to Express Uncertainty about a Decision

Be in Two Minds

Meaning: to be unable to decide between two possibilities.

Register: Neutral and particularly common in British English.

The American equivalent is often be of two minds.

• I’m in two minds about whether to go to the mountains or the seaside.
• Jeremy was in two minds about going to work because he felt unwell.

Natural patterns include:

• be in two minds about something
• be in two minds about whether to do something
• be in two minds as to whether

Avoid saying:

• I’m in two minds whether to go.

A more natural version is:

• I’m in two minds about whether to go.

Be Inclined to Think or Believe

Meaning: to have a particular opinion without being completely certain about it.

Register: Neutral to formal.

This expression allows you to give an opinion cautiously.

• I’m inclined to think that travelling in this weather is not a good idea.
• The residents were inclined to believe that the new security system was inadequate.

This is particularly useful in discussions and speaking exams because it sounds thoughtful rather than overly definite.

• I’m inclined to think that working from home offers more advantages than disadvantages.

---

Formal Ways to Express Uncertainty in English

It Remains to Be Seen

Meaning: it is not yet known what will happen or whether something will be successful.

Register: Neutral to formal.

This expression is often used when the result will become clear in the future.

• It remains to be seen whether the new environmental law will be effective.
• Whether we will win the match remains to be seen.

This phrase is very useful in essays, reports and formal discussions.

As Far as I Know

Meaning: according to the information you currently have, although you may not be completely certain.

Register: Neutral.

• As far as I know, the meeting is still scheduled for Monday.
• As far as I know, nobody has complained about the changes.

This expression shows that your statement may be correct but that you cannot guarantee it.

I Cannot Say for Certain

Meaning: I am unable to give a completely definite answer.

Register: Neutral to formal.

• I cannot say for certain when the repairs will be finished.
• We cannot say for certain what caused the accident.

A more conversational form is:

• I couldn’t say for sure.

There Is a Possibility That

Meaning: something may happen or may be true.

Register: Neutral to formal.

• There is a possibility that the event will be postponed.
• The possibility that the flight may be cancelled is causing concern.

You can vary the strength of the possibility:

• a slight possibility
• a real possibility
• a strong possibility
• a distinct possibility

---

Useful Phrases for Expressing Uncertainty

Here are some additional expressions you can use in conversation, writing and exams:

• I’m not entirely convinced that…
• I may be wrong, but…
• I cannot be sure, but…
• It is difficult to say whether…
• There is some doubt as to whether…
• I would not rule out the possibility that…
• Perhaps…
• Possibly…
• Apparently…
• Presumably…
• In all likelihood…
• From what I understand…
• To the best of my knowledge…

Examples

• I may be wrong, but I think the office closes at five.
• It is difficult to say whether the changes will be beneficial.
• From what I understand, the decision has not yet been finalised.
• I would not rule out the possibility of further delays.
• To the best of my knowledge, no formal complaint has been made.

---

Expressing Different Degrees of Uncertainty

Not every expression communicates the same level of doubt.

Slight uncertainty	I think…, I believe…, As far as I know…
Moderate uncertainty	I’m not sure…, It is difficult to say…, I may be wrong, but…
Strong doubt	I have serious doubts…, I’m sceptical…, I remain unconvinced…
Complete uncertainty	I cannot say for certain…, It remains to be seen…
Indecision	I’m in two minds…, I haven’t made up my mind…
Suspicion	I’m dubious about…, That sounds rather doubtful…
Confusion	I’m bewildered…, I can’t make sense of it…

Ways to Express Uncertainty in English in Speaking Exams

In a speaking exam, it is better to develop your answer than simply say I don’t know.

Try these sentence starters:

• I’m not entirely sure, but I would imagine that…
• It is difficult to say because…
• I may be wrong, but my impression is that…
• I’m inclined to think that…
• As far as I know…
• It remains to be seen whether…
• I cannot say for certain, although…
• There is a possibility that…

Example

Question: Do you think people will work fewer hours in the future?

It is difficult to say, but I’m inclined to think that technology will reduce the amount of routine work people have to do. However, it remains to be seen whether employers will use those savings to give workers more free time.

Common Mistakes

Incorrect: I am doubt about the plan.

Correct:

• I have doubts about the plan.
• I am doubtful about the plan.
• I doubt that the plan will work.

Incorrect: I am sceptical for his explanation.

Correct:

• I am sceptical about his explanation.
• I am sceptical of his explanation.

Incorrect: I am in two minds whether to accept.

Better: I am in two minds about whether to accept.

Incorrect: We made an uncertain agreement.

Better: We reached a tentative agreement.

A tentative agreement has not yet been fully confirmed.

---

Practice Exercise

Choose the most suitable expression to complete each sentence.

1. The dates are still __________ and may change.
2. I’m __________ whether to accept the job or continue my studies.
3. The journalist was __________ about the accuracy of the figures.
4. __________, the museum is closed on Mondays.
5. The long-term effects of the policy remain __________.
6. The instructions were so complicated that I felt completely __________.
7. I’m __________ to think that a compromise would be the best solution.
8. The committee remains __________ by the company’s explanation.
9. It seems __________ that the work will be completed by tomorrow.
10. I cannot say for __________ what caused the problem.

Answers: 1. tentative, 2. in two minds about, 3. sceptical, 4. As far as I know, 5. to be seen, 6. bewildered, 7. inclined, 8. unconvinced, 9. doubtful, 10. certain

---

Final Thoughts

There are many ways to express uncertainty in English, but they are not all interchangeable.

Use not sure or uncertain when you lack definite information. Use sceptical, dubious or unconvinced when you doubt a claim or idea. Choose tentative for plans and agreements that have not been confirmed, and use in two minds when you cannot make a decision.

By choosing the expression that matches your precise meaning, you will sound clearer, more natural and more confident—even when you are not completely certain.

Related posts:

• Stronger Ways to Express Certainty
• Other Ways to Say “I Don’t Know” in English 
• How to Express Doubt in English
• Expressing Probability in English 
• Expressing Opinions and Arguments in English 
• Talking about Choices in English 
• B2 First Speaking 
• C1 Advanced Speaking 

Visit our bookshop for more English study materials