with this table, you will be able to understand the different functions Modal verbs have . Example and substituting verbs and expressions are also given
|Modal Verb||Function||Substituting verb|
|can||could||• Ability – John can speak English, but he can’t speak Spanish.
• Ability (in the past) – My mother could swim when she was younger.
• Possibility – I can learn English.
• Permission – Can I go out please?
• Offer – Can I help you, madam?
• Request – Could you bring me a cup of tea, please?
|• To be able to
• To be capable of
• To be (im)possible to
• To be allowed to
|May||Might||• Permission (politeness) – May I open the window, please?
• Possibility – The chauffeur may be in the car.
Susan may not come tomorrow.
You might participate in the contest.
• Probability – It might rain.
|• To be allowed to
• To be likely to
• To be probable to
• Perhaps… will
|Will||Would||• Requests (more polite) – Would you mind closing the door?
• Determination/intention – I will pass the exam.
|• To want
• To desire
• To be determined to
|Shall ||Should||• Offer – Shall I open the door for you?
• Suggestion – Shall we go to the cinema?
• Advice – You should eat more vegetables.
|• Do you want…?
• To have to (morally)
• To be the (moral) duty
• … Would better…
|Must/Have to ||Had to||• Obligation/duty – You must do your homework, whether you want to or not.
• Deduction – He has a great car. He must earn a lot of money.
• Necessity – You must go to the doctor if you can’t see well.
|• To have to
• To be obliged to
• To have the obligation
• To be certain
|Mustn’t||• Prohibition – You mustn’t cross the road when the red light is on.||• To be forbidden
• To be prohibited to
|Ought to||• Recommendation/moral obligation – You ought to study more.||• To have to|
|Need/Needn’t||• (Absence of) obligation/necessity – You needn’t run. It’s still early.||• To be necessary
• Don’t need to
• Don’t have to
|Dare ||• Audacity or lack of it – How dare you?/He daren’t look at me.||• To have the courage to|