Modals – Intermediate Level

Modals

Modal verbs — expressing ability, permission, obligation, possibility, etc.

Modal verbs are auxiliary verbs that modify the meaning of a main verb to express ability, permission, obligation, necessity, likelihood, requests, offers, and advice.

They are followed by the base form of the main verb (not ‘to verb’).

Common features:

  • no -s in third person singular
  • form questions and negatives without ‘do’
  • and have distinct present/past meanings or uses.


Main modal verbs and uses:

Can

  • Ability (present): I can swim.
  • Permission (informal): Can I leave early?
  • Possibility: It can get cold here at night.
  • Requests (informal): Can you help me?

Could

  • Past ability: When I was young I could run fast.
  • Polite permission/request: Could I borrow your pen?
  • Possibility (less certain than can): It could rain later.
  • Conditional ability: I could help if I had time.

May

  • Permission (formal): You may enter the room.
  • Possibility (formal/neutral): We may arrive late.

Might

  • Possibility (less certain): She might come tonight.
  • Polite suggestion (weaker): You might try restarting the phone.
  • Past in reported speech: He said he might go.

Must

  • Obligation/necessity (strong): You must wear a seatbelt.
  • Logical conclusion/certainty: She must be at work by now.
  • Note: For prohibition use must not / mustn’t: You mustn’t smoke here.

Have to / Has to (semi-modal; not a pure modal)

  • External obligation/necessity: I have to finish this by tomorrow. (used for obligations imposed by circumstances or others)
  • Past: had to.

Should

  • Advice/recommendation: You should see a doctor.
  • Expectation/probability: They should arrive soon.
  • Obligation (milder than must): You should apologize.

Ought to (semi-modal)

  • Advice/moral obligation: You ought to tell the truth.
  • Usually follows with to: ought to + verb.

Shall

  • Offers/suggestions (first person, formal or British): Shall I open the window?
  • Formal future (legal/very formal): The company shall provide insurance.

Will

  • Future simple: I will call you tomorrow.
  • Volition/willingness: I will help you.
  • Promises/offers: I will pay for dinner.
  • Predictions: It will be sunny.

Would

  • Polite requests/offers: Would you like some tea?
  • Conditional mood: I would go if I could.
  • Past habit (polite/time reference): When we were kids, we would play outside.
  • Reported speech for will: He said he would come.

Need (to) / Needn’t (modal-like behavior)

  • Necessity with to: I need to study.
  • Absence of necessity (modal negative): You needn’t come if you’re busy.

Dare (modal when used without to)

  • Challenge or boldness: How dare you!
  • Negative/questional modal use: Dare he ask? / He daren’t say it. (less common)

Semi-modals and modal phrases

  • Be able to — ability (works in all tenses):

    She was able to solve it.

  • Have got to — obligation (informal):

    I’ve got to go now.

  • Be supposed to — expected duty or arrangement:

    You are supposed to finish by Friday.

  • Be allowed to — permission (varies by tense/agent):

    Are we allowed to take photos?

  • Used to — past habitual action (modal-like):

    I used to play piano.


Negatives, questions, and short answers

  • Form negatives by adding ‘not’ after the modal:

    She cannot (can’t) come; He should not (shouldn’t) go.

  • Form questions by inverting modal + subject:

    You can swim.
    Can you swim?
    They will arrive.
    Will they arrive?

  • Short answers use modal (or auxiliary) + pronoun:

    Can you help?
    “Yes, I can.”
    “No, I can’t.”


Past reference and perfect meaning with modals

Use modal + have + past participle to talk about past possibility, speculation, or criticism:

Examples:

  • She might have missed the train. (possibility about past)
  • You should have told me. (criticize past action)
  • He must have left already. (logical conclusion about past)
  • They could have won if they’d tried. (ability/opportunity in the past)


Degrees of certainty (common scale)

Certain: must (logical certainty)
Probable: should, ought to
Possible: may, might, could
Remote/unreal conditional: would, could (with if-clauses)

Modals with Passive

  • Modal + be + past participle forms passive meanings:
    • The problem can be solved.
    • The meeting should be canceled.

  • Past possibility passive:
    • The window might have been broken.


Common Pitfalls and Notes

  • Do not add -s to modals in third person singular:

    Correct: He can (not “He cans”).

  • Use have to for obligation in many present and past constructions (I had to work yesterday).
  • Distinguish must (internal logical necessity or strong obligation) from have to (external requirement).
  • Ought to is followed by to; most other modals are followed by bare infinitive.
  • For polite requests and offers, prefer could/would/might over can/will in formal contexts.

Quick-Reference Examples

  • Ability:
    • She can speak four languages.
    • He was able to lift it.
  • Permission:
    • May I come in?
    • You may not use your phone.
  • Obligation:
    • You must stop at a red light.
    • I have to pay taxes.
  • Advice:
    • You should study more.
    • You ought to apologize.
  • Requests:
    • Could you pass the salt?
    • Would you help me?
  • Possibility:
    • It might snow tonight.
    • That must be the answer.
  • Future/willingness:
    • I will call you.
    • She would help if asked.
  • Past speculation:
    • He must have missed the bus.
    • They could have won.