Auxiliary Verbs Matrix
Modal Auxiliary Verbs: Complete Guide & Rules
Master Can, Could, May, Might, Must, Shall, Should, Will, Would, and Ought to with clear usage charts and examples.
3 Golden Rules of Modal Verbs
- No "-s" in 3rd Person: Never say "he cans" or "she musts". Always use "he can" and "she must".
- Followed by Base Verb (V1): Always pair with the bare infinitive without "to" (except ought to): "I must study", NOT "I must to study".
- No "Do/Does" in Questions or Negatives: Say "Can you help?" and "You should not worry".
| Modal Verb | Primary Functions | Example Sentence |
|---|---|---|
| Can | Present ability, informal permission, possibility | "She can solve complex equations with ease." |
| Could | Past ability, polite request, weak possibility | "Could you please share the exam timetable?" |
| May | Formal permission, moderate probability, wishes | "May I come in? / It may rain tonight." |
| Might | Remote possibility, tentative suggestion | "Dark clouds are gathering; it might rain." |
| Must | Strong obligation, necessity, logical deduction | "Candidates must carry a valid photo ID." |
| Should | Advice, recommendation, expectation | "You should revise irregular verbs before the test." |
| Ought to | Moral duty, social responsibility | "Citizens ought to respect public heritage." |
| Will | Future certainty, promise, willingness | "I will complete the assignment by Friday." |
| Would | Polite offer, conditional, past habit | "Would you like a cup of warm tea?" |
| Shall | Formal offer, suggestion (1st person), legal rule | "Shall we begin the debate now?" |
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