💡 Gist: What Are Modal Verbs?

Modal verbs are helping verbs that add special meaning to the main verb in a sentence.
They help express ideas like ability, possibility, permission, advice, obligation, and imaginary situations.

There are nine main modal verbs in English:

👉 Can, Could, Shall, Should, Will, Would, May, Might, Must

They never stand alone — they always come with the base form of a verb (V₁).
✅ I can swim.
❌ I can swims.

🧭 Basic Rules for Using Modal Verbs

1️⃣ Always use the base verb after a modal:
✔ She can dance well.

2️⃣ Never add “-s” in the third person:
✔ He can drive. ❌ He cans drive.

3️⃣ Negatives:
She cannot (can’t) come. / You shouldn’t lie.

4️⃣ Questions:
Can I help you? / Should we start now?

🔹 Main Functions of Modal Verbs

1️⃣ Ability

Express what someone can or could do.

• Can → Present ability: I can swim fast.

• Could → Past ability: When I was a child, I could run fast.

2️⃣ Possibility

Show how likely something is to happen.

• Must → Strong probability: She must be tired.

• May / Might → Weaker possibility: It may rain later.

• Cannot / Could not → Impossibility: That can’t be true!

3️⃣ Deduction & Speculation

Used for making smart guesses based on clues.

• Must → He must be at work; his car is gone.

• Should → They should be home by now.

• Might / Could → He could be sleeping.

• Can’t → She can’t be serious!

4️⃣ Advice & Suggestions

Used for guidance or polite recommendations.

• Should / Must → You should drink water. / You must try this.

• Could / Might → You could join a gym. / You might check that again.

• Shall (in questions) → Shall we sit in the balcony?

• Ought to → You ought to help your parents.

5️⃣ Permission & Requests

Used to ask for or give permission.

• Can → Informal: Can I borrow your pen?

• May → Formal: May I come in, sir?

• Could → Polite: Could I please use your phone?

📘 Anecdote:
Once, a student asked, “Can I go out?”
The teacher smiled and said, “You can, but you may not.”
👉 Can = ability, May = permission.

6️⃣ Obligation & Prohibition

Show duty, necessity, or restriction.

• Must → You must wear a seatbelt.

• Have to → I have to finish my homework.

• Should → You should be honest.

• Mustn’t → You mustn’t smoke here.

• Shouldn’t → You shouldn’t lie.

7️⃣ Hypothetical / Conditional Situations

Used in “If” sentences or imaginary cases.

• Would → If I had time, I would travel.

• Could → If it stops raining, we could go out.

• Might → If you tried, you might succeed.

✨ Expressing Uncertainty or Politeness

Modals help make speech softer or more polite.

• It might rain later.

• She could be at the office.

• They should arrive soon.

🎯 Summary Table of Common Modal Verbs

🔹 List of Common Semi-Modal Verbs

1️⃣ Ought to

👉 Meaning: Moral duty, advice, or right action

• You ought to respect your elders.

• We ought to obey the rules.

• Students ought to be punctual.

🧭 Notes:

• Similar in meaning to should but stronger in moral sense.

• Negative form → ought not to
  ✅ You ought not to waste time.

2️⃣ Have to

👉 Meaning: Obligation or necessity (external requirement)

• I have to wear a uniform at school.

• You have to complete your homework before playing.

• Soldiers have to follow orders.

🧭 Notes:

• Used for rules or laws given by someone else (not your own decision).

• Negative form → don’t have to (means not necessary, not forbidden).
  ✅ You don’t have to come if you’re busy.

3️⃣ Need to

👉 Meaning: Necessity or requirement

• You need to study harder.

• We need to leave early.

• He needs to improve his handwriting.

🧭 Notes:

• Similar to must, but softer in tone.

• Negative form → don’t need to (means it’s not necessary).
  ✅ You don’t need to worry about that.

4️⃣ Used to

👉 Meaning: Past habit or past situation (no longer true now)

• I used to play cricket every day.

• She used to live in Delhi.

• We used to have a dog.

🧭 Notes:

• Refers only to past habits or states.

• Negative → didn’t use to
  ✅ I didn’t use to like vegetables.

5️⃣ Dare (to)

👉 Meaning: To have courage or boldness to do something

• He dared to speak the truth.

• I don’t dare to go there alone.

• How dare you talk like that?

🧭 Notes:

• Can be used with or without “to”.
  ✅ I dare not go there. (modal use)
  ✅ I don’t dare to go there. (semi-modal use)

🎯 Summary Table