Modal-Like Expressions with “be”
These expressions combine a form of “be” (am, is, are, was, were, been) with another word or phrase, followed by an infinitive (to + base verb). They allow us to convey specific types of obligation, expectation, certainty, or imminent action.
“be supposed to” (Expectation, Obligation, General Belief)
This expression indicates what is expected, obligatory, or generally believed to be true. It often implies a plan, a rule, or a duty.
That new movie is supposed to be very good. (People say it’s good.)
Expectation/Arrangement: Used for plans or arrangements that are (or were) expected to happen.
We were supposed to meet some friends at seven. (This was our plan/arrangement.)
The package is supposed to arrive tomorrow. (This is the expectation.)
Obligation/Rule: Implies that something is a rule or a duty.
You are supposed to wear a uniform. (It’s a rule.)
Students are not supposed to use their phones during class. (It’s forbidden.)
What is generally believed: Used to state what people commonly think or say.
“be about to” (Immediate Future)
This expression indicates that an action is going to happen very, very soon – it’s on the verge of happening.
I think I am about to fall asleep.
Immediate Action:
We were about to leave the house, but she couldn’t find her keys. (We were literally at the point of leaving.)
The train is about to depart. Please stand clear of the doors.
“be bound to” (Certainty, Inevitability)
This expression conveys a strong sense of certainty or inevitability. It suggests that something is very likely to happen, almost guaranteed, due to natural consequences or existing circumstances.
He’s so talented; he’s bound to succeed.
Strong Certainty/Inevitable Outcome:
Her keys were bound to be in the house somewhere. (It was almost certain they would be there.)
If you don’t study, you’re bound to fail the exam. (It’s the inevitable consequence.)
“be forced to” (Compulsion, Lack of Choice)
This expression indicates that someone has no choice but to do something, usually due to external circumstances, rules, or pressure. It implies compulsion.
- External Compulsion:
- We were forced to go room by room looking for them. (We had no other option.)
- The company was forced to close due to financial problems.
- I am forced to work overtime this week.
“be sure to” (Strong Expectation/Certainty, or Strong Recommendation)
This expression has two main uses, both implying a high degree of confidence or advisability:
Make sure to submit your assignment on time.
Strong Expectation/Certainty: Similar to “be bound to,” but can also refer to a deliberate action someone will certainly take.
They’re sure to be neatly placed side by side on the floor. (A very confident prediction or assumption.)
He’s sure to call you as soon as he lands.
Strong Recommendation/Advisability (often used in commands or advice): Encourages or advises someone to definitely do something.
Be sure to lock the door when you leave. (Strong advice/command.)
📌 Structure
| Expression | Tense | Example |
|---|---|---|
| be supposed to | Present, Past, Future | I am supposed to meet him. We were supposed to call. |
| be about to | Present, Past | She is about to leave. They were about to start. |
| be bound to | Present, Past | It is bound to happen. He was bound to find out. |
| be forced to | Present, Past, Present Perfect, etc. | I am forced to agree. They were forced to sell. |
| be sure to | Present, Past (less common), Imperative | You are sure to succeed. Be sure to tell me! |
📝 Notes
- The verb “to be” must be conjugated correctly (
am, is, are, was, were) to match the subject and the tense you want to express. - The expression is always followed by the infinitive with “to” (
to + base verb). - These expressions add a specific nuance that simple modal verbs might not capture. For example, “You should go” is advice, while “You are supposed to go” implies an expectation or a rule.
- “Be bound to” and “be sure to” can both express certainty, but “bound to” often suggests an inherent or inevitable outcome, while “sure to” can also be a strong recommendation.
💬 Examples
✅ Positive Examples
- We were supposed to meet some friends at seven.
- The concert is about to begin.
- Her keys were bound to be in the house somewhere.
- The flight was forced to land due to bad weather.
- He’s a great speaker; he’s sure to impress everyone.
❌ Negative Examples
- You are not supposed to park here.
- I wasn’t about to give up after all that effort.
- The plan is not bound to succeed without more resources.
- They weren’t forced to sign the contract.
- Don’t worry, she’s not sure to notice the small mistake.
❓ Question Examples
- Are we supposed to bring anything?
- Was he about to tell us something important?
- Are they bound to agree with the decision?
- Were you forced to work late?
- Are you sure to remember everything?
Ready to Express Ability and Obligation in New Ways in English?
Mastering modal-like expressions with “be” (like “be able to,” “be supposed to,” “be going to”) is a fantastic step to expanding your ability to talk about necessity, expectation, and future plans. They add versatility to your English!
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