The intuition: a prediction that follows from a reason
We use be bound to when, in our view, things can hardly turn out otherwise: there is a reason that makes the result almost inevitable. The speaker is not merely guessing but drawing on what they know about people, things or circumstances.
The explanation can appear nearby with because/so or already be clear from the conversation. You’re bound to enjoy it is a complete, natural utterance even without a separate reason in the same sentence.
subject + am/is/are bound to + base verb
- subject / S —
- The grammatical subject: who or what the clause is about; the verb agrees with it. In The book was written, the book is the subject, although someone else does the action.
- verb / V —
- A word for an action or state, such as work or be. The pattern determines its form.
- V1 / base form —
- The base verb without to: work, go, be.
You've left your phone in the rain again, so it's bound to stop working soon.
You've left your phone in the rain again, so it's bound to stop working soon.
The reason (rain) leads directly to the conclusion; the speaker has almost no doubt.
Every new flatmate is bound to ask where the spare key is.
Every new flatmate is bound to ask where the spare key is.
The prediction is based on experience: this happens every time.
Lena skipped the briefing, so she's bound to be confused.
Lena skipped the briefing, so she's bound to be confused.
Be can also follow bound to: bound to be + adjective.
Degrees of certainty: bound to compared with likely to and might
On a scale of certainty, might and could merely allow a possibility, likely to expresses probability, and be bound to places the event close to certainty. It is this difference in strength, not in time, that the listener hears.
Do not intensify this already very strong construction with very or more: a sentence such as It is very bound to rain sounds wrong. For degrees of likelihood, use likely to, covered in a neighbouring rule; for certainty, keep bound to without intensifiers.
The road is bound to be busy on the first day of the holidays.
The road is bound to be busy on the first day of the holidays.
The speaker is almost certain.
The road is likely to be busy on the first day of the holidays.
The road is likely to be busy on the first day of the holidays.
The same event, but with weaker confidence.
The road might be busy on the first day of the holidays.
The road might be busy on the first day of the holidays.
The speaker merely allows for the possibility.
Form: be + bound + to + base verb
The first part changes according to the subject (am, is, are; in the past, was, were), followed by bound to and then a base verb without endings or -ing. In a question, be moves to the beginning; in conversation it is often contracted: she’s, they’re.
In there is/are bound to be, agreement depends on the noun after be: singular takes there is, plural takes there are. This pattern is very common for predictions that something is certain to exist or happen.
There + is/are + bound to be + noun
- noun —
- A word naming a person, thing or idea: student, book, happiness.
Our landlord is bound to complain about the noise.
Our landlord is bound to complain about the noise.
The subject is singular, so use is; after to, use complain without an ending.
The neighbours are bound to hear that music.
The neighbours are bound to hear that music.
The subject is plural, so use are.
There is bound to be a catch.
There is bound to be a catch.
The noun phrase a catch is singular, so use there is.
There are bound to be crowds at the beach.
There are bound to be crowds at the beach.
The noun crowds is plural, so use there are.
Register and alternatives
Be bound to is common in conversation but is also possible in writing or workplace messages. Certain to, will inevitably and it is inevitable that can convey similar strong certainty; choose the form to suit the particular text.
Do not consider bound to automatically unsuitable simply because the context is formal. If an exercise explicitly asks for a particular construction, that is a learning requirement; in your own writing, the meaning and a natural tone matter.
Say what you like — a long speech is bound to bore them.
Say what you like — a long speech is bound to bore them.
Conversational tone, strong certainty.
Rents are certain to rise over the next year.
Rents are certain to rise over the next year.
A neutral or more formal version of the same idea.
Further delays are inevitable.
Further delays are inevitable.
A formal alternative without the verbal construction.
Past time and negation
Was/were bound to describes an event that seemed inevitable from a past perspective: it was clear that it would happen. It is usually a retrospective comment or an explanation of why nobody was surprised.
Isn’t bound to can mean “will not necessarily happen” or, in another context, “is not obliged to”. This is not the same as “certainly will not happen”. For the latter meaning, she is certain not to… or she certainly won’t… is clearer.
He was bound to find out sooner or later.
He was bound to find out sooner or later.
From the past perspective, this seemed inevitable. The sentence itself does not confirm whether he has already found out.
The old car was bound to break down on such a long trip.
The old car was bound to break down on such a long trip.
The reason (an old car, a long trip) explains the inevitability.
She's certain not to forget the date.
She's certain not to forget the date.
Certainty about a negative outcome is expressed with certain not to.
Limits: obligation, commands and schedules
Bound also has another meaning: “obliged” by law, a contract or rules. Context distinguishes the two meanings: legal or contractual circumstances indicate obligation, while observations about people and circumstances indicate a prediction. This rule practises the prediction meaning.
Bound to is not used as a command or request: use be sure to for a reminder. When an event is scheduled and will occur according to plan, use be due to, covered in a separate rule. Probability without full certainty is expressed with likely to.
The company is legally bound to refund the fee.
The company is legally bound to refund the fee.
This is an obligation, not a prediction.
Be sure to lock the door when you leave.
Be sure to lock the door when you leave.
A reminder uses be sure to here, not be bound to.
The train is due to leave at six.
The train is due to leave at six.
A schedule is a separate meaning, covered in a neighbouring rule.
Common mistakes
Incorrect:The tourists are bound getting lost in the old town.
Correct:The tourists are bound to get lost in the old town.
Bound needs to followed by a base verb; an -ing form is not possible here.
Incorrect:Our guests are bound to arriving late tonight.
Correct:Our guests are bound to arrive late tonight.
The to-part takes the base form arrive, not arriving: to is an infinitive marker here, not a preposition.
Incorrect:Your sister bound to be furious about the broken vase.
Correct:Your sister is bound to be furious about the broken vase.
Without a form of be (am/is/are), the construction is incomplete: the subject cannot stand directly beside bound to.
Incorrect:It is very bound to rain on Saturday.
Correct:It is bound to rain on Saturday.
Bound to already expresses near certainty, so very does not intensify it; use likely to for degrees of likelihood.
Incorrect:Be bound to call me when you land.
Correct:Be sure to call me when you land.
A command or reminder is not expressed with be bound to; it requires be sure to.