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Grammar

Modal Verbs — Advice, Possibility & Obligation

can, could, should, must, might, would — the verbs that let you give advice, soften requests, and express how sure you are. Core to Speaking Tasks 1 and 7.

7 min read
Key strategies
  • 1.A modal is always followed by the BASE verb: "should go", never "should to go" or "should goes".
  • 2.Advice: should / ought to. Strong necessity: must / have to. Possibility: may / might / could.
  • 3.Use could / would / might to sound more polite and less blunt: "Could you...?" is softer than "Can you...?".
  • 4.For past advice you did not follow, use "should have + participle": "I should have studied more."

The golden rule

A modal verb is always followed by the base form of the next verb — no to, no -s, no -ed:

✓ "She should call him." ✗ "She should to call him." ✗ "She should calls him."

What each modal does

  • Advice: should, ought to — "You should rest."
  • Obligation / necessity: must, have to — "Drivers must stop at red lights."
  • Possibility: may, might, could — "It might rain later."
  • Ability: can, could — "I can swim." "She could read at four."
  • Permission / polite requests: can, could, may — "Could I leave early?"

Politeness through modals

Past-form modals sound softer and more polite, which matters in Speaking:

"Could you help me?" is gentler than "Can you help me?" "I would suggest taking the train." is gentler than "Take the train."

should have — past regret/advice

To comment on a past action that was a mistake, use should have + past participle:

"I should have booked earlier." (but I didn't)

CELPIP application

Modals are the backbone of Speaking Task 1 (Giving Advice) — "If I were you, I would...", "You should...", "You could try..." — and of expressing balanced opinions in Task 7.

Check yourself

A quick self-check on this lesson — pick an answer, then see the explanation. Not graded.

1. Choose the correct form:
2. Which is the most polite request?
3. Past regret: "I ___ saved more money last year."
4. Strong necessity (a rule): "Passengers ___ wear a seatbelt."

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