Modal Verbs – Present Modal
Must, Have to, Should 3

MUST, HAVE TO, and SHOULD

⚖️MUST, HAVE TO, and SHOULD

📝These modal verbs are used to talk about rules, obligations, and advice. Each one has a different meaning.

👉Formula reminder:

must + base verb
have to + base verb
should + base verb

1️⃣MUST – Internal Obligation 💡

🧠We use must when the obligation comes from inside (our own decision, strong feelings, or authority speaking).

📚I must study for my exam. (I decide it's necessary)
👂You must listen carefully! (teacher's authority)
🤫We must be quiet in the library. (strong rule)

2️⃣HAVE TO – External Obligation 📋

🏢We use have to when the obligation comes from outside (a rule, law, or someone else's decision).

👕We have to wear uniforms at school. (school rule)
🚦Drivers have to stop at red lights. (law)
💼He has to finish his report by tomorrow. (boss's order)

👉Difference:

💭must = I feel/decide it's necessary.
📜have to = someone else's rule/requirement.

3️⃣SHOULD – Advice 👍

💡We use should to give advice, recommendations, or suggestions.

🍎You should eat more fruit. (good idea)
📖He should study harder if he wants to pass.
🏰They should visit London – it's beautiful.

4️⃣Comparison Table

Modal	Type of Meaning	Example
must	Internal obligation (personal decision / strong necessity)	I must call my mom now.
have to	External obligation (rule/law/requirement)	We have to wear a seatbelt.
should	Advice or recommendation	You should drink more water.

5️⃣Common Mistakes ❌✅

❌I must to study.
✅I must study.
❌She have to wear a uniform.
✅She has to wear a uniform.
❌You should to sleep more.
✅You should sleep more.

✨Quick Tips

💭Use must when it's your own feeling or a strong authority.
📜Use have to when it's a rule or law.
💡Use should when it's just advice, not an obligation.

🔧Formation Rules

📋Positive:

Subject + MUST/HAVE TO/SHOULD + base verb

📋Negative:

Must: Subject + MUST NOT (mustn't) + base verb
Have to: Subject + DON'T/DOESN'T HAVE TO + base verb
Should: Subject + SHOULD NOT (shouldn't) + base verb

📋Question:

Must: MUST + subject + base verb?
Have to: DO/DOES + subject + HAVE TO + base verb?
Should: SHOULD + subject + base verb?

📝More Examples

💡MUST Examples (Internal/Personal):

⏰I must leave now or I'll be late!
💧You must drink water when you exercise.
🚫We mustn't forget to call grandma.

📋HAVE TO Examples (External/Rules):

🎫You have to buy a ticket to enter.
👨‍⚕️Patients have to wait in the waiting room.
🚫Children don't have to pay for the bus.

👍SHOULD Examples (Advice):

🌞You should wear sunscreen at the beach.
💰We should save money for emergencies.
🚫He shouldn't eat so much junk food.

💭Remember

💡MUST = internal feeling, personal decision, or strong authority
📋HAVE TO = external rule, law, or requirement
👍SHOULD = advice, suggestion, or recommendation
📝All three use the base verb (no "to")
⚠️Have to changes: has to for he/she/it
🚫Mustn't = prohibition, don't have to = not necessary

Modal Verbs – Present Modal Must, Have to, Should 3