Be supposed to




be supposed to
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When to use supposed to

To be supposed to is a common phrase that functions the same way a modal verb does. Modal verbs, also called auxiliary or helping verbs, add meaning to the main verb in a sentence by expressing possibility, ability, permission, or obligation. Supposed to, like have to, can fall into the “obligation” category.


1) to be expected to do something

They are supposed to arrive tomorrow.

She was supposed to be here an hour ago.

The movie was supposed to earn a lot of money at the box office, but it didn't.


2) to be intended or expected to be something

The party was supposed to be a surprise.


3) —used to show that one is angry or offended by something

Was that supposed to be funny? I thought it was quite rude.

"Well, you've done it again." 

"What's that supposed to mean?"


4) —used to say what someone should do

You are supposed to listen to your parents.

I'm supposed to clean my room before I go outside.

What are we supposed to do in a situation like this?

Do what you're supposed to.


5) —used to refer to what someone is allowed to do

We were not supposed to leave the room.

Are you supposed to be here after the building has closed?


6) —used to indicate what people say about someone or something

"I heard that she's good." 
"She is supposed to be the best doctor in town.

"That breed of dog is supposed to be good with kids.

The word is supposed to be derived from Latin.
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The verb to suppose

On the other hand, the verb to suppose means to presume, in theory, that something is the case without certain evidence.

Prakash isn’t here yet, so I suppose his train was delayed.

The committee supposes that the decline in profits is due to a faulty product design.

As an imperative, it can mean the equivalent of what would happen if.

Suppose my coach really does turn into a pumpkin. What will I do then?

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Supposed to, have to, and ought to

Some English language learners are easily confused by the modal verbs to be supposed to, have to, and ought to. 

While all three function similarly in a sentence, their meanings are subtly different.


To be supposed to do something implies that the subject is obligated and expected to do the main verb’s action, although there is a possibility it won’t happen.


The magician is supposed to pull a rabbit out of his hat.

Here, there is an expectation that the magician will be able to perform his trick correctly, but there is always a chance that he won’t succeed. The sentence conveys this expectation, and the reader must now wait to see if that expectation will be fulfilled.


Has to means the same as must; it implies that the subject has no choice about performing the verb’s action.


The magician has to produce the rabbit to earn applause.

This sentence conveys that if the magician does not produce the rabbit, there will be no applause. He simply must do it to get the result he wants.


Ought to is more of a suggestion. It conveys what would be best for the subject to do, but the subject is not compelled to do it.


The magician ought to slip his rabbit a carrot before the show.

To ensure that he has a compliant, content rabbit in his hat, the magician should give his rabbit a carrot, although no one requires it of him. It would simply be a good idea.