Modal verbs

It is forbidden to smoke in public places. 

• You can
• You must
• You mustn't
• You have to 

You are obliged to finish this work before the end of the week. 

• have to
• needn't
• can
• might 

I am sure it is not true.

• This must be 
• This may be
• This can't be 
• This shouldn't be

You needn't call her - she already knows the news. 

• don't have to
• shouldn't
• can't
• mustn't

It is obligatory for students to take part in this curse. 

• Students can 
• Students should
• Students  could
• Students have to 

Smoking is banned here. 

• Smoking is allowed
• Smoking is possible
• Smoking is forbidden
• Smoking is obligatory

We are allowed to drink water in class. 

• We may not
• We needn't
• We can
• We must 

It is possible that it will rain tomorrow. 

• It may 
• It must 
• It should 
• It can't

I am sure Sara needs our help.

• Sara can need
• Sara must need
• Sara may need
• Sara doesn't have to need

I know how to play the piano. 

• I can 
• I may
• I must
• I need to