Modals and their Function

• Can

  Ability/Opportunity
• Could

  General Ability
• May

  Future Possibility/Get Permission
• Might

  Possibility
• Should

  Advice or Strong Suggestion
• Must

  Very strong advice/obligation
• Mustn't

  Things you're not allowed to do
• Have to/Has to

  In the present/Near future
• Had to

  in the past
• will have to

  in the future
• Doesn't have to/Don't have to

  it isn't necessary
• Be supposed to

  Expectation
• Be allowed to

  Permission
• be able to

  show an ability