Expressing Certainty and Uncertainty

Learn how to express how sure or unsure you are about something

Video Lesson

Tip: Certainty and uncertainty are used to express how sure or unsure we are about something. These expressions are commonly used in both spoken and written English. Using appropriate expressions of certainty and uncertainty makes your communication more precise and nuanced!

Expressing Certainty

When you are sure about something, you can use the following expressions:

  • I'm sure/certain that...
  • There's no doubt that...
  • It's crystal clear that...
  • It's obvious that...
  • It's evident that...
  • No one can deny that...
  • Definitely,...
  • Certainly,...
  • Undoubtedly,...

Examples:

  • I'm certain that climate change is affecting our planet.
  • There's no doubt that technology has improved our lives.
  • It's obvious that regular exercise is good for health.

Expressing Uncertainty

When you are not sure about something, you can use the following expressions:

  • I'm not sure/certain that...
  • I doubt that...
  • I guess...
  • Maybe...
  • Perhaps...
  • Probably...
  • Possibly...
  • It's unlikely that...
  • It's doubtful that...

Examples:

  • I'm not sure that this solution will solve all our problems.
  • Perhaps we should consider other options.
  • It's unlikely that prices will decrease soon.

Practice: What is expressed in these statements?

InstructionWrite "C" for certainty, and "U" for uncertainty.

1. There's no doubt that Artificial Intelligence will replace humans in many sectors.

2. No one can deny that many young people are wasting their time on gaming and social networks.

3. It's doubtful that scientists will find a cure to cancer in the next 5 years.

4. It's evident that Information technology has changed our lifestyles.

5. It's unlikely that technology could solve all problems faced by humans.