Modals and Their Uses

Front

Necessity or obligation (official tone because of rule or law)

Back

Must

Front

Necessity or obligation (unofficial tone, more for personal needs)

Back

Have to

Front

Prohibition

Back

Must not, may not, cannot

Front

Broken rule

Back

be not supposed to

Front

Expectation

Back

be supposed to

Front

Advice

Back

Should

Front

Warning

Back

Had better (not)

Front

Not necessary

Back

not have to

Front

Permission

Back

Can/May/Be allowed to/Be permitted to

Front

Present Ability or Inability

Back

Can, Cannot, Be able to, be not able to