Expressing prohibitions and obligations - bdmlass

Expressing prohibitions

Prohibition can be found at many places such as at schools, hospitals, at museums, on a plane even at house so learn to express prohibition is essentially important for English language learners as to better understand to use prohibition. Here are the expressions that are frequently used to express prohibitions. 

Be not allowed to + base verb….

• Students are not allowed to eat or sleep in the classroom.
• It is not allowed to smoke in the hospital.
• Passengers are not allowed to go to the toilet when the plane is taking off.
• People are not allowed to walk on the grass here.
• Students are not allowed to use phones during the exam.

Be not permitted to + base verb......

• Students are not permitted to bring soft drink into the classroom.
• Teachers are not permitted to accept student's expensive presents. 
• Passengers on the plane are not permitted to change seat.
• It not permitted to bring in pets into this building. 

Be prohibited to + base verb………….

• Students are not prohibited to eat or sleep in the classroom.
• It is prohibited to smoke in the hospital.
• Passengers are prohibited to go to the toilet when the plane is taking off.
• People are prohibited to walk on the grass here.
• Students are prohibited to use phones during the exam.

Be forbidden to + base verb ...............

• It is forbidden to enter this area at night.
• It is forbidden to bring in any form of explosives. 
• It is forbidden throw the trash on the streets.

Can't + base verb ......

• Students can't eat during the lesson.
• We can't park here.
• You can't talk on the phone when you are driving.

Mustn't + base verb ....

• Passengers must not smoke on the bus.
• Students must not make noise during the lesson.
• We mustn't park at the no park sign.

Expressing an obligation

External rules/ laws

Sub + have to + base verb ......

• Students have to do homework regularly.
• Teachers have to wear a tie at school.
• In Cambodia, people have to drive on the right.
• We have to stop when the light is red.
• People have to pay income tax every month.

Internal rules or obligations, determination, necessity

To express personal or internal ruler or obligations, modal verb "must" is used.

Sub + must + base verb....

• You must finish your work by today.
• He must study harder to pass the exam.
• I must stop drinking coffee.
• We must grow more trees.
• People must work together to stop global warming.

No obligations

To express something that is not an obligation or something that is not necessary to do, use don't have to.

Sub + don't/doesn't have to + base verb.

• You don't have to take off you shoes here. It is not required.
• I don't have to wear a uniform on Friday. 
• You don't have to tip the taxi driver in Cambodia but I can do it if you like.
• We don't have to get up early on Sunday.