08/07/2021
π Modals
Permission, Prohibition, Obligation, No obligation
To express permission, prohibition, obligation and no obligation we usually use modal verbs.
π Permission
Can is often used to ask for and give permission.
Can I sit here?
You can use my car if you like.
Can I make a suggestion?
We can also use may and could to ask for and give permission but can is used more
often.
π Prohibition
Both canβt and mustnβt are used to show that something is prohibited β it is not allowed.
You canβt park here, sir.
You can wear jeans but you canβt wear trainers in that bar.
You mustnβt speak when the teacher is speaking.
Canβt tells us that something is against the rules. Mustnβt is usually used when the obligation comes from the person who is speaking.
π Obligation
Have to and must are both used to express obligation. There is a slight difference between the way they are used.
Have to shows us that the obligation comes from somebody else. Itβs a law or a rule and the speaker canβt change it.
Do you have to wear a uniform at your school?
John canβt come because he has to work tomorrow.
In Britain you have to buy a TV licence every year.
Must shows us that the obligation comes from the speaker. It isnβt a law or a rule.
I must call my dad tonight.
You must hand in your homework on Tuesday or your mark will be zero.
You must come and visit us the next time you come to London.
π No obligation
We use donβt have to to show that there is no obligation. You can do something if you want to but itβs not compulsory.
You donβt have to wear a tie in our office. You can wear a tie if you want to but itβs OK if you donβt.
Itβll be nice if you do but you donβt have to come with me if you donβt want to.
You donβt have to dress up for the party. Wear whatever you feel comfortable in.