The second set of functions for modals and modal-like expressions you will focus on in this unit is expressing expectation, obligation, and necessity.
Should
In Grammar 7-1, you reviewed how to use the modal verb should to give advice. It can also be used to express expectation, or what one believes will be true.
- Veronika should be here a little after 5 PM depending on the traffic.
This sentence expresses that the speaker expects that Veronika will be here at that time. They don't know for sure but think it is likely to happen because it is logical or normal. This function of should is usually used to refer to the present or near future.
- The potatoes should be cooked by now; can you see if they’re done?
- The money from the settlement should be in your bank account by the end of the month.
- The new regulations should address people’s biggest concerns about the city parks.
You can also express an expectation for something not to happen by using should not. In many cases, this is contracted to shouldn’t.
- Don’t worry; it shouldn’t take long for her to grade your essay.
- People shouldn’t be smoking inside, so the smell must be coming from the patio.
- Finding a solution to the problem shouldn’t be too difficult.
Necessary
Necessary, of course, helps us to express necessity. Necessity simply means that something is necessary, essential, or required. You can use the following structure to express this.
be + necessary + infinitive verb
Note that this structure is frequently used with the impersonal it.
- The rules are necessary to make sure everyone is playing fairly.
- It’s necessary to register before you can vote.
- Is it necessary to be there so early? The flight doesn’t leave until 3 PM.
To make it clearer who the necessity applies to, you can add for + noun to the structure.
- Is it necessary for all visitors to sign in before they enter the courthouse?
- She doesn’t think it will be necessary for you to bring anything to the party.
- It’s necessary for all of us to remain calm and try to figure things out.
You can express a lack of necessity by adding not. In some cases, this expresses that the action or state is optional.
- Luckily, it wasn’t necessary for my mother to stay in the hospital for long.
- It is not necessary for the government to find out what people think about every single issue.
- It is not necessary to be so formal; this is a pretty casual office.
Sometimes, not necessary can be used as a criticism of someone’s behaviour.
- It’s not necessary for you to be so rude!
Supposed to
Supposed to expresses and communicates obligations, that is, things that must be done because of a duty, rule, or law.
The following structure is used with supposed to.
be + supposed to + base form
- Your landlord is supposed to give you 24 hours’ notice before entering your apartment.
- These laws are supposed to be followed, but not everyone does.
- All visitors are supposed to sign in when they arrive at the hospital.
Like the examples above, adding not will express things you are obligated not to do.
- These boxes are not supposed to be here. They must be moved out immediately.
- The media is not supposed to show only one side of the story.
- He is not supposed to do that work; it’s not his responsibility.
In some situations, supposed to (with or without not) can also express expectation in a similar way to should (above).
- The presentation is supposed to start as soon as everyone gets settled in their seats.
- The weather is not supposed to be very good later this week.
- The governor's speech is supposed to discuss the issue of affordable housing.