Grammar: B1 - 🔑 Modals & Related Structures: Certainty, Possibility, Advice, Obligation - Lesson 1: Modals of Obligation & Necessity (must, have to, don't have to, mustn't

ESL Cambodia 🇰🇭

Must vs. Have to

Rules & Obligation (កាតព្វកិច្ច)

🟢 Must

Necessary
ត្រូវតែ

🔴 Mustn't

Prohibited
ហាមឃាត់

🟡 Don't have to

Not Needed
មិនចាំបាច់

✅ Obligation (ត្រូវតែធ្វើ)

You must stop at red lights.

អ្នកត្រូវតែឈប់នៅស្តុបក្រហម

I have to wear a uniform.

ខ្ញុំត្រូវតែស្លៀកឯកសណ្ឋាន (ច្បាប់)

🚫 Prohibition (ហាមដាច់ខាត)

You mustn't smoke here.

អ្នកមិនត្រូវជក់បារីនៅទីនេះទេ

🤷‍♂️ No Obligation (មិនចាំបាច់)

You don't have to pay. It's free.

អ្នកមិនចាំបាច់បង់លុយទេ វាឥតគិតថ្លៃ

⚠️ Careful!
"Mustn't" = Do NOT do it. (Bad!)
"Don't have to" = You can choose. (Okay!)

Traffic Police 👮‍♂️

Dara gets stopped.

Police 👮‍♂️

Stop! You must wear a helmet.

Dara 🧑

I'm sorry. Do I have to pay a fine?

Police 👮‍♂️

Yes. You mustn't drive without one. It is dangerous.

Dara 🧑

Do I have to go to the station?

Police 👮‍♂️

No, you don't have to go there. You can pay here.

Check Rules 🚦

Pick the correct modal.

Scenario: At the library (Silence required).

You ___ talk loudly.

Scenario: Tomorrow is Sunday (No work).

I ___ work tomorrow.

Scenario: Entering a Pagoda.

You ___ take off your hat.

Mission 📝

Classroom Rules!

Write Rules:

Think about your English class.

• 1. Students must listen to the teacher.
• 2. Students mustn't _______________.
• 3. Students don't have to _______________.

(Ideas: speak Khmer, wear uniform, use phone)