Grammar: ⚙️ Verbs in Depth: 🎭 Modals & 🌱 Non-Finite Verbs (Advanced) (B2) - Lesson 2: Modals of Deduction & Speculation - Past (must have been, might have V3, couldn't have V3)

Advanced Verbs B2

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Past Deduction

ការសន្និដ្ឋានអំពីអតីតកាល

We use modals + have + V3 to make guesses about the past based on evidence we see now.

យើងប្រើប្រាស់ទម្រង់នេះ ដើម្បីស្មាន ឬទាញសេចក្តីសន្និដ្ឋានអំពីអ្វីដែលបានកើតឡើងក្នុងអតីតកាល ដោយផ្អែកលើភស្តុតាងបច្ចុប្បន្ន។

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99% Sure (Yes)

ច្បាស់ជា (ជឿជាក់ស្ទើរតែ ១០០%)

Evidence: The street is wet.

It must have rained.

/mʌst həv reɪnd/ វាច្បាស់ជាបានភ្លៀងហើយ។

Evidence: Someone ate my cake.

It must have been my brother!

/mʌst həv bɪn/ វាច្បាស់ជាបងប្រុសខ្ញុំហើយ!

🤷

50% Sure (Maybe)

ប្រហែលជា (មិនសូវប្រាកដ)

Evidence: He is late for the meeting.

He might have missed the bus.

/maɪt həv mɪst/ គាត់ប្រហែលជាជិះឡានក្រុងមិនទាន់។

Evidence: I can't find my keys.

I could have left them at work.

/kʊd həv lɛft/ ខ្ញុំប្រហែលជាបានភ្លេចវានៅកន្លែងធ្វើការ។

🙅

99% Sure (No)

មិនអាចទៅរួចទេ (ជឿជាក់ថាវាមិនបានកើតឡើង)

Evidence: She was with me all day.

She couldn't have stolen the car.

/ˈkʊdnt həv ˈstoʊlən/ នាងមិនអាចលួចឡាននោះទេ (ព្រោះនាងនៅជាមួយខ្ញុំ)!

Evidence: He doesn't speak French.

He can't have translated this.

/kænt həv trænsˈleɪtɪd/ គាត់មិនអាចបកប្រែវារួចទេ!

The "Mustn't Have" Trap!

Do not use "mustn't have" for deduction.

(ប្រយ័ត្ន! សម្រាប់ការសន្និដ្ឋានបដិសេធ យើងប្រើ "can't have" ឬ "couldn't have"។ យើងមិនសូវប្រើ "mustn't have" ទេ ព្រោះវាមានន័យថា "ហាមឃាត់" មិនមែន "មិនអាចទៅរួចទេ" ។)

He mustn't have seen me. ❌
He couldn't have seen me. ✅

Mastery Check ⚡

ការត្រួតពិនិត្យកម្រិតខ្ពស់

Positive Deduction

The ground is completely wet.

It ___ rained last night.

(ដីសើមជោគ។ វាច្បាស់ជាបានភ្លៀងកាលពីយប់មិញ។)

Possibility

I can't find my keys, but I'm not sure where they are.

I ___ left them at the office.

(ខ្ញុំប្រហែលជាបានភ្លេចវានៅកន្លែងធ្វើការ។)

GRAMMAR TRAP! ❌

He was in Siem Reap at the time!

He ___ robbed the bank here!

(គាត់មិនអាចទៅរួចទេដែលប្លន់ធនាគារនៅទីនេះ!)

Meaning Check

"She must have forgotten."

តើប្រយោគនេះមានន័យដូចម្តេច?

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Mission 🎯

អនុវត្តផ្ទាល់!

The Detective 🕵️‍♂️ (ស្រមៃថាអ្នកឃើញបន្ទប់មួយរាយប៉ាយ។ សរសេរប្រយោគមួយដោយប្រើ "must have" ដើម្បីសន្និដ្ឋានពីអ្វីដែលបានកើតឡើង។ ឧ. A dog must have come inside.)

🖊️

Mission 🎯

អនុវត្តផ្ទាល់!

The Missing Pen 🖊️ (អ្នករកប៊ិចមិនឃើញ។ សរសេរប្រយោគមួយដោយប្រើ "might have" ដើម្បីស្មានពីកន្លែងដែលវាបាត់។)

🗣️

Mission 🎯

អនុវត្តផ្ទាល់!

Voice Note 🎤 (ថតសំឡេងខ្លួនឯងអានការសន្និដ្ឋានទាំងពីរខាងលើឲ្យបានច្បាស់ល្អ។)

Play Detective

មេរៀនជាវីដេអូ

Context is Key: Watch how Teacher Sopheak looks at the clues *first* before making a deduction using these advanced modals.

Ask a Question 🙋‍♂️

តើអ្នកមានចម្ងល់មែនទេ? សួរគ្រូនៅទីនេះ!

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Advanced Q&A

S

Sovan 2 hours ago

Teacher, what is the difference between "may have" and "might have"?

Reply 👍 15

SP

Sopheak Pich Teacher 1 hour ago

Good question! Basically, they are the same and you can use them interchangeably for past deduction. Some grammar books say "might" is slightly *less* probable than "may", but in real life, nobody notices the difference! 🕵️‍♂️

V

Vireak 5 hours ago

Is there a difference between "could have" and "might have" in deduction?

Reply 👍 8

SP

Sopheak Pich Teacher 4 hours ago

In deduction (guessing), they are very similar. However, "could have" has another meaning: it means someone had the *ability* to do something in the past, but chose not to. (e.g., "I could have won the race, but I stopped to tie my shoe"). 👟