Grammar: B1 - 🔑 Modals & Related Structures: Certainty, Possibility, Advice, Obligation - Lesson 3: Modals of Possibility & Probability (may, might, could - present/future)

🔑 Lesson 3: Modals of Possibility & Probability

Sometimes, we don't know something for sure. When we want to talk about possibility¹ (what can happen) or probability² (how likely it is), we use modal verbs. Today, we will learn how to use may, might, and could to speculate³ about the present and future when we don't have 100% certainty⁴.

Expressing Positive Possibility

When you think something is possible (but not 100% certain), you can use 'may', 'might', or 'could'. In many situations, these words are interchangeable⁵ and express about a 50% chance of something being true.

Structure: Subject + may / might / could + verb (infinitive)

• A: "Where is Sothea?" B: "I don't know. He might be at the market."
• "Look at those dark clouds over the river. It could rain this afternoon."
• "I'm not sure about my plans for the holiday. I may go to visit my family in the countryside."

Expressing Negative Possibility

To say that it's possible something will *not* happen, we use "may not" or "might not".

Structure: Subject + may not / might not + verb (infinitive)

• "Hurry up, or we might not get a good seat at the circus."
• "He is feeling sick, so he may not come to class tomorrow."

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Important: We do not use "couldn't" to talk about negative possibility in the same way. "Couldn't" usually talks about something that was impossible in the past (e.g., "I couldn't open the door"). For present/future possibility, use may not or might not.

How to Ask About Possibility

It can sound unnatural to ask a question with "May...?" or "Might...?". Instead, it is more common to use a phrase like "Do you think...?".

Instead of: Might it rain later?
Say this: "Do you think it will rain later?"

Instead of: Could he be at home?
Say this: "Is it possible that he's at home?"

🧠 Practice Quiz: What's Possible?

Choose the best option to complete each sentence.

1. A: "Where is the manager?" B: "I'm not sure. She _______ be in a meeting."
   Answer: might / may / could (All three are correct for positive possibility.)
2. Don't wait for me. I _______ be late tonight because the traffic is bad.
   Answer: might / may
3. Be careful with that old glass! It _______ break.
   Answer: could / might
4. He feels very sick, so he _______ come to work tomorrow.
   Answer: might not / may not (We cannot use 'couldn't' here.)
5. This plan is risky. It _______ work, but we should at least try it.
   Answer: may not / might not

📝 Homework: Make Some Guesses

Write a sentence for each situation using the modal verbs of possibility.

1. Look at the sky outside now (or imagine it). What is the weather like? Make a prediction for the next hour using "might".
   (Example: The sky is very grey. It might rain soon.)
   _________________________________________
2. Your friend did not answer their phone. Give two possible reasons why. Use "may" and "could".
   (Example: She may be driving her moto. She could be in the shower.)
   _________________________________________
3. Think about your plans for next weekend. What is one thing you might do?
   (Example: I might go to a cafe with my friends on Sunday.)
   _________________________________________

Vocabulary Glossary

1. Possibility: (Noun) - លទ្ធភាព (lŏt'thĕ'phéap) - A chance that something may happen or be true. ↩
2. Probability: (Noun) - ប្រូបាប៊ីលីតេ (pro'ba'bi'li'te) - The level of possibility of something happening or being true. ↩
3. Speculate: (Verb) - សន្និដ្ឋាន (sân'nĭ'tʰaan) - To guess possible answers to a question when you do not have enough information to be certain. ↩
4. Certainty: (Noun) - ភាពប្រាកដប្រជា (phéap praa'kât'prâ'chea) - The state of being completely confident or having no doubt about something. ↩
5. Interchangeable: (Adjective) - អាចផ្លាស់ប្តូរបាន (aach phleah'bdaur'baan) - Able to be exchanged with each other without making a difference or without being noticed. ↩