Likely, Unlikely, Bound To, Certain To: Expressing Probability
Grammar Rule in 30 Seconds
Use these phrases to express how confident you are about a future event happening.
- Use 'bound to' for near-certainty: 'It is bound to rain.'
- Use 'likely' for high probability: 'They are likely to arrive soon.'
- Use 'unlikely' for low probability: 'It is unlikely to snow today.'
These expressions let you grade how probable something is — from near certainty to low probability — without using modal verbs.
bound to — almost certain (inevitable)
✅ She is bound to pass — she studied for months.
✅ There is bound to be traffic at this time.
likely / unlikely to — probable / improbable
✅ It is likely to rain tomorrow.
✅ She is unlikely to change her mind.
Also: It is likely that she will pass.
certain to — guaranteed
✅ He is certain to be late — he always is.
| Expression | Certainty | Example |
|---|---|---|
| bound to | ~95% | She's bound to pass. |
| certain to | ~95% | He's certain to be late. |
| likely to | ~70% | It's likely to rain. |
| unlikely to | ~30% | It's unlikely to change. |
Formation of Probability Modals
| Subject | Be Verb | Expression | Infinitive |
|---|---|---|---|
|
I
|
am
|
likely to
|
go
|
|
You
|
are
|
bound to
|
win
|
|
He/She/It
|
is
|
certain to
|
arrive
|
|
We
|
are
|
unlikely to
|
fail
|
|
They
|
are
|
likely to
|
succeed
|
Contractions
| Full Form | Contraction |
|---|---|
|
I am likely to
|
I'm likely to
|
|
He is bound to
|
He's bound to
|
|
They are certain to
|
They're certain to
|
Meanings
These expressions function as adjectives or adverbial modifiers to indicate the speaker's degree of certainty regarding future outcomes.
High Probability
Something is expected to happen based on evidence.
“It is likely to rain later.”
“She is likely to get the promotion.”
Inevitability
Something is almost guaranteed to happen.
“He is bound to make a mistake eventually.”
“This project is bound to succeed.”
Certainty
The speaker has no doubt about the outcome.
“They are certain to be there.”
“The sun is certain to rise tomorrow.”
Reference Table
| Form | Structure | Example |
|---|---|---|
|
Affirmative
|
Subj + be + likely to + V
|
It is likely to rain.
|
|
Negative
|
Subj + be + unlikely to + V
|
It is unlikely to rain.
|
|
Question
|
Be + Subj + likely to + V?
|
Is it likely to rain?
|
|
Bound To
|
Subj + be + bound to + V
|
He is bound to win.
|
|
Certain To
|
Subj + be + certain to + V
|
She is certain to pass.
|
|
Short Answer
|
Yes, it is / No, it isn't
|
Is it likely? Yes, it is.
|
Formality Spectrum
The project is certain to be completed by Friday. (Work deadline)
The project is likely to be finished by Friday. (Work deadline)
The project is bound to be done by Friday. (Work deadline)
The project's gonna be done, for sure. (Work deadline)
Probability Spectrum
High
- Certain to 100%
Medium-High
- Bound to 90%
Probable
- Likely to 70%
Low
- Unlikely to 20%
Examples by Level
It is likely to rain.
He is likely to come.
It is unlikely to be cold.
They are likely to win.
The bus is likely to be late.
She is certain to pass the test.
It is unlikely to happen today.
We are bound to have fun.
The economy is likely to improve next year.
This mistake is bound to cause problems.
It is unlikely that he will change his mind.
They are certain to arrive by noon.
The project is bound to face some resistance.
Given the data, it is highly likely to succeed.
It is unlikely to be a simple solution.
The results are certain to be published soon.
Such a policy is bound to exacerbate existing tensions.
It is statistically unlikely to occur twice.
The outcome is certain to reshape the industry.
He is likely to be appointed as the new director.
The proposed changes are bound to meet with significant opposition.
It is highly unlikely to yield the desired results.
The consensus is that the trend is certain to continue.
Such an approach is likely to prove counterproductive.
Easily Confused
Learners often confuse the adjective 'likely' with the preposition 'like'.
Both imply necessity, but 'bound to' is for prediction, 'must' is for obligation.
They are synonyms, but 'certain to' is more formal.
Common Mistakes
It is likely rain.
It is likely to rain.
He is bound to success.
He is bound to succeed.
It is not likely to.
It is unlikely to.
She is likely that she comes.
She is likely to come.
They are certain that win.
They are certain to win.
It is likely happen.
It is likely to happen.
He is bound that he wins.
He is bound to win.
It is bound to be happening.
It is bound to happen.
It is likely to have happened.
It is likely to happen.
She is certain to be win.
She is certain to win.
It is highly bound to happen.
It is bound to happen.
It is unlikely to not happen.
It is likely to happen.
The result is certain to be occurred.
The result is certain to occur.
Sentence Patterns
It is ___ to happen.
He is ___ to win.
The results are ___ to be positive.
This ___ to be a mistake.
Real World Usage
It is likely to rain.
The stock is bound to rise.
I'm likely to be late.
I am certain to bring value.
The flight is likely to be delayed.
Your order is bound to arrive soon.
Use 'unlikely' for negatives
Don't forget the 'to'
Bound to = Inevitable
Formal vs Informal
Smart Tips
Use 'likely' instead of 'will' to sound more objective.
Use 'bound to' for strong conviction.
Use 'unlikely' to hedge.
Use 'bound to' for excitement.
Pronunciation
Likely
Stress the first syllable: LIKE-ly.
Bound to
The 'd' in bound often blends into the 't' in to.
Falling
It is LIKELY to RAIN.
Conveys certainty and finality.
Memorize It
Mnemonic
Remember 'L-B-C': Likely (Maybe), Bound (Strong), Certain (Yes).
Visual Association
Imagine a scale. 'Likely' is a light breeze, 'Bound to' is a heavy anchor, 'Certain' is a solid stone wall.
Rhyme
Likely to happen, bound to be true, certain to follow, through and through.
Story
I am likely to go to the party. I am bound to see my friends there. I am certain to have a great time.
Word Web
Challenge
Write 3 predictions for your day using each of the three phrases.
Cultural Notes
Often use 'bound to' more frequently than Americans.
Tend to use 'likely' in professional settings.
Avoids 'bound to' as it sounds too informal/subjective.
The word 'likely' comes from Old Norse 'ligr', meaning 'like'.
Conversation Starters
What is likely to happen in the news tomorrow?
Is it bound to rain this weekend?
Are you certain to finish your project on time?
What is unlikely to change in the next ten years?
Journal Prompts
Common Mistakes
Test Yourself
It is ___ to rain tomorrow.
Which is correct?
Find and fix the mistake:
It is unlikely that he will to come.
Arrange the words in the correct order:
All words placed
Click words above to build the sentence
Es probable que gane.
Answer starts with: He ...
Match each item on the left with its pair on the right:
A: Will he pass? B: Yes, he is ___.
Use 'unlikely' and 'happen'.
Score: /8
Practice Exercises
8 exercisesIt is ___ to rain tomorrow.
Which is correct?
Find and fix the mistake:
It is unlikely that he will to come.
to / rain / is / likely / it
Es probable que gane.
Match 'bound to' with its meaning.
A: Will he pass? B: Yes, he is ___.
Use 'unlikely' and 'happen'.
Score: /8
FAQ (8)
No, 'likely' as an adjective needs 'to' + verb.
No, it's quite common in speech.
'Likely' is probability, 'certain' is 100% sure.
Yes, but 'unlikely' is more common.
Usually for the future, but can be used for logical deduction about the past.
It's part of the infinitive construction.
Yes, 'Is it likely to rain?'
Yes, they are very common for hedging.
Scaffolded Practice
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2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Es probable que...
English uses 'to + verb', Spanish uses a subordinate clause.
Il est probable que...
English uses the infinitive.
Es ist wahrscheinlich...
German word order changes.
～だろう (darou)
Japanese is agglutinative.
من المحتمل أن...
Arabic grammar is root-based.
很可能 (hěn kěnéng)
Chinese has no verb conjugation.
Learning Path
Prerequisites
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