PREPARATION

B1 • Lesson 39

Degrees of Certainty

Vocabulary and reading to prepare for your lesson

Target Vocabulary

Click each word to see its meaning and an example.

Key Words

certainty / certain noun / adjective

Complete confidence that something is true; sure and definite.

"I can say with certainty that this approach will succeed."

likely / unlikely adjective

Probable; having a strong chance of happening or being true.

"It's likely that we'll finish the project on time."

possible / impossible adjective

Able to happen or be true; able to occur.

"It's possible that there are other solutions we haven't considered yet."

probability noun

The likelihood that something will happen.

"The probability of success depends on many factors."

doubtful / doubt adjective / noun

Uncertain or skeptical; a feeling of not being sure.

"I'm doubtful that this method will work given past experiences."

confidence noun

A feeling of being sure about something.

"I have confidence that the plan will work based on the evidence."

Speaking Chunks

I'm certain / I'm sure chunk

Used to express very high confidence in something.

"I'm certain that this is the best option available."

I think / I believe / In my opinion chunk

Used to express a moderate level of confidence.

"In my opinion, we should move forward with this plan."

It's likely that / It's probable that chunk

Used to suggest something has a good chance of happening.

"It's likely that we'll see results within a few weeks."

It's possible / It might be chunk

Used to express lower certainty about something.

"It's possible that we'll need to adjust our strategy."

I doubt that / I'm doubtful chunk

Used to express skepticism or lack of confidence.

"I doubt that approach will be cost-effective in the long term."

I'm confident that chunk

Used to express strong belief based on evidence or experience.

"I'm confident that this team has the skills to complete the project."

Reading: Expressing Appropriate Levels of Confidence

In professional and academic communication, being able to express varying degrees of certainty is important. You need to communicate how confident you are about your ideas, predictions, and conclusions. Using the right language helps you appear knowledgeable and credible, while using the wrong language can make you seem either arrogant or weak.

There's a spectrum of certainty in English. At one end, we have absolute statements: "This is definitely true" or "I'm certain." At the other end, we have expressions of doubt: "I doubt that" or "It's unlikely." In between, there are moderate expressions: "I think," "It's possible," or "It's likely." Choosing the right expression depends on your actual level of confidence based on evidence.

It's important to match your language to your actual confidence. If you have strong evidence, use confident language like "I'm certain" or "The data clearly shows." If you're less sure, use more cautious language like "It seems," "It might be," or "It's possible that." Mismatching language to evidence looks dishonest or uninformed.

In business and academic settings, being appropriately cautious is valued. It shows intellectual honesty—you're not overstating what you know. At the same time, being too cautious makes you sound uncertain and untrustworthy. The goal is to find a balance that reflects your actual confidence level based on available evidence.

Developing this skill makes your communication more credible and persuasive. People trust speakers who honestly acknowledge both what they're confident about and what remains uncertain or doubtful.

~310 words • B1 Level

Discussion Questions

Think about these questions before your lesson. You don't need to write answers—just consider your thoughts.

Keyword Speaking Practice

For each question above, write maximum 3 keywords — no sentences. Then practise speaking your answer out loud from just the keywords.

Q1: "Do you tend to be confident or cautious when making predictions or stating opinions?"

Your 3 keywords: / /

Now say your answer out loud. Speak for about 30 seconds from just your keywords.

Q2: "Can you think of a time when you were too confident or not confident enough in expressing an idea?"

Your 3 keywords: / /

Speak for 30 seconds. Let your brain build the sentences from the keywords.

Q3: "How do you decide what level of certainty to use when discussing something new or unfamiliar?"

Your 3 keywords: / /

Say your answer out loud — don't just think it! Your keywords are enough.

Remember: keywords only. Your brain does the rest. Mistakes are good — they mean you're practising speaking, not reading.

Start Lesson 39 →

Preparation time: ~15 minutes