Speaking: Grammar in Speaking B2 - Lesson 5: Using Modals for Speculation (must be, might have)

Speaking B2

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Speculation

ការទាយ ឬសន្និដ្ឋានដោយប្រើកិរិយាសព្ទជំនួយ

How to sound like a detective when you aren't 100% sure!

រៀនប្រើប្រាស់ Modals ដើម្បីទាយពីអ្វីមួយនៅពេលដែលអ្នកមិនប្រាកដក្នុងចិត្ត។

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Present Speculation 🔍

ការសន្និដ្ឋានបច្ចុប្បន្ន

Rule: Modal + Verb (Base form) to guess what is happening NOW.

99% Sure it IS Must be He has a Ferrari. He must be rich. (គាត់មានឡាន Ferrari។ គាត់ប្រាកដជាអ្នកមាន។)

50% Sure Might / Could be She is late. She might be stuck in traffic. (នាងមកយឺត។ នាងប្រហែលជាស្ទះចរាចរណ៍។)

99% Sure it IS NOT Can't be He ate 3 pizzas. He can't be hungry. (គាត់ញ៉ាំភីហ្សាអស់ ៣។ គាត់មិនអាចឃ្លានទៀតទេ។)

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Past Speculation 🕰️

ការសន្និដ្ឋានអតីតកាល

Rule: Modal + HAVE + V3 (Past Participle) to guess what happened in the PAST.

99% Sure it HAPPENED Must have + V3 The ground is wet. It must have rained. (ដីសើម។ វាប្រាកដជាបានភ្លៀងហើយ។)

50% Sure Might have + V3 I can't find my keys. I might have left them at home. (ខ្ញុំរកសោមិនឃើញទេ។ ខ្ញុំប្រហែលជាបានភ្លេចវានៅផ្ទះ។)

99% Sure it DIDN'T HAPPEN Can't have + V3 She can't have stolen it; she was with me! (នាងមិនអាចលួចវាទេ ព្រោះនាងនៅជាមួយខ្ញុំ!)

Grammar Traps!

Trap: Can't vs Mustn't

When you are 99% sure something is impossible, use Can't be, not "Mustn't be"!

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He just ate. He mustn't be hungry. ❌
He just ate. He can't be hungry. ✅
("Mustn't" is for rules/prohibition: You mustn't smoke here.)

Quick Check ⚡

ការត្រួតពិនិត្យរហ័ស

100% Sure (Present)

You have been working for 12 hours. You ___ exhausted!

(អ្នកប្រាកដជាហត់នឿយខ្លាំងណាស់!)

Past Speculation

Dara's car is gone. He ___ already.

(ឡានរបស់ដារ៉ាបាត់ហើយ។ គាត់ប្រាកដជាចេញទៅបាត់ហើយ។)

THE TRAP! ❌

That ___ John! John is currently in Japan.

(នោះមិនអាចជា ចន ទេ! ចនឥឡូវកំពុងនៅជប៉ុន។)

50% Sure (Past)

She didn't come to the party. She ___ sick.

(នាងមិនបានមកកម្មវិធីជប់លៀងទេ។ នាងប្រហែលជាឈឺហើយ។)

Speaking Context

"He isn't answering his phone."
"He ___."

(គាត់ប្រហែលជាកំពុងដេកហើយ។)

Mission 🎯

អនុវត្តផ្ទាល់!

People Watcher 🕵️‍♂️ (សម្លឹងមើលជនចម្លែកម្នាក់ រួចសន្និដ្ឋានការងាររបស់គេក្នុងចិត្ត ឧ. "He's wearing a suit. He must be a businessman.")

Mission 🎯

អនុវត្តផ្ទាល់!

Write a Mystery ✍️ (សរសេរប្រយោគមួយដោយប្រើ "must have + V3" ពីនរណាម្នាក់ដែលលួចញ៉ាំនំរបស់អ្នក!)

Mission 🎯

អនុវត្តផ្ទាល់!

Teach a friend 🙋‍♂️ (ពន្យល់មិត្តភក្តិរបស់អ្នកថាហេតុអ្វីបានជាយើងមិនប្រើ "Mustn't be" សម្រាប់ការសន្និដ្ឋាន!)

Mission 🎯

អនុវត្តផ្ទាល់!

Voice Note 🎤 (ថតសំឡេងខ្លួនឯងពណ៌នាពីវត្ថុមួយដែលអ្នកបានបាត់កាលពីមុន ហើយប្រើពាក្យ "I might have left it..." រយៈពេល ៣០ វិនាទី។)

Video Lesson

មេរៀនជាវីដេអូ

Ask a Question 🙋‍♂️

តើអ្នកមានចម្ងល់មែនទេ? សួរគ្រូនៅទីនេះ!

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Recent Questions

S

Sokha 2 hours ago

Native speakers say "musta" and "mighta". Is this correct?

Reply 👍 15

SP

Sopheak Pich Teacher 1 hour ago

Yes! In fast spoken English, "must have" sounds like "must've" or "musta". "Might have" sounds like "might've" or "mighta". It's a great trick to sound more natural when speaking! 🗣️

V

Vireak 5 hours ago

Can I use "could have" instead of "might have"?

Reply 👍 8

SP

Sopheak Pich Teacher 4 hours ago

Absolutely. For past speculation, "might have," "may have," and "could have" all mean basically the same thing (around 50% certainty). E.g., "He could have missed the bus." 🚌

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Dara 8 hours ago

Why is "mustn't be" a trap?

Reply 👍 5

SP

Sopheak Pich Teacher 7 hours ago

Because "mustn't" is used for rules (You mustn't touch the art). It means "Don't do it!". But when we are guessing and we think something is impossible, we use "Can't". (It can't be true!) 🛑