Talking about possibility and probability

Q: What are modal verbs of possibility?

Modal verbs of possibility, such as may , might , and could , are "helping" verbs used to say that something is "maybe" true or likely to happen.

Q: What is the standard sentence pattern for using modal verbs of possibility?

The pattern is Subject + Modal Verb + Action Word (Base Form) .

Q: In modern English, how is might often distinguished from may ?

Might is often considered a "weak maybe," used for things that are even less likely to happen than those described with may .

Q: Which modal verbs represent "Low Certainty" (20-50%) on the Certainty Meter?

The modal verbs might , could , and may represent low certainty.

Q: When should you use the modal verb must to express probability?

Use must when you are almost certain (about 90%) because you have strong evidence to support your guess.

Q: What does the modal verb will indicate on the Certainty Meter?

Will indicates very high certainty (99-100%) and is used for facts or very strong predictions.

Q: When should you use can't instead of might not ?

Use can't when you are 100% sure that something is impossible.

Q: Which modal verbs are typically used for making suggestions about possibilities?

The modal verbs can or may are often used to suggest possible solutions or actions.

English Language · Junior Secondary · 4 min read

Talking About Possibility and Probability

Welcome! In this chapter, we are going to explore how to use modal verbs to talk about things that might happen or things we are guessing about. Whether you are wondering if it will rain later or guessing who left a mysterious note on your desk, these words help you express how sure (or unsure) you are.

Don't worry if this seems a bit tricky at first. We use these words in every conversation, and once you see the patterns, you will be a pro!

1. What are Modals of Possibility?

Modal verbs are special "helping" verbs. When we talk about possibility, we are saying that something is "maybe" true or "maybe" going to happen. The most common words we use are may, might, and could.

How to use them:
The pattern is very simple: Subject + Modal Verb + Action Word (Base Form).
Example: It (Subject) + might (Modal) + rain (Action).

Real-World Examples:
1. "I may go to the library after school." (I haven't decided yet, but it is a possibility.)
2. "Take an umbrella. It might rain later." (There is a small chance of rain.)
3. "Where is Sam? He could be in the canteen." (This is one possible place he is hiding!)

Did you know?
In modern English, may, might, and could are very similar. However, many people feel that might is used for things that are even less likely than may. Think of might as a "weak maybe."

Key Takeaway: Use may, might, or could when you are not 100% sure about something.

2. The "Certainty Meter": How Sure Are You?

Imagine a "Certainty Meter" that goes from 0% to 100%. Different modal verbs sit at different points on this meter.

Low Certainty (20-50%): might, could, may
Use these when you are just guessing.
Example: "The key might be in my bag."

High Certainty (90%): must
Use must when you are almost certain because you have strong evidence.
Example: "The lights are on. They must be at home."

Very High Certainty (99-100%): will
Use will when you are sure it is a fact or a strong prediction.
Example: "The sun will rise tomorrow."

Quick Review:
- Guessing? Use might.
- Almost sure? Use must.
- Totally sure? Use will.

3. Saying "No": Negative Possibility

When we think something is not possible, we add the word not. However, be careful! The meaning can change.

May not / Might not: This means "maybe not."
Example: "We might not have a test tomorrow." (Maybe we will, maybe we won't.)

Can't: This means you are sure something is impossible.
Example: "That can't be the Principal. He is on holiday!" (You are 100% sure it is not him.)

Memory Aid: The "Must vs. Can't" Trick
- Use must for "Yes, I'm sure!"
- Use can't for "No, it's impossible!"

4. Making Predictions and Assumptions

In your syllabus, you will see that we often use modals to make assumptions (educated guesses) or predictions about the future.

Making Predictions:
We often use will or won't for predictions based on what we think.
Example: "Technology will make our lives easier."

Making Suggestions:
We can use can or may to suggest possibilities.
Example: "The government can build more parks to improve our city."

Key Takeaway: When predicting, will is for things you are sure about, while could or might are for things that are just possible.

5. Watch Out! Common Mistakes

Mistake 1: Adding "to" after the modal.
Incorrect: It might to rain.
Correct: It might rain. (Never use "to" after may, might, must, or could!)

Mistake 2: Adding "-s" for he/she/it.
Incorrect: She mays be late.
Correct: She may be late. (Modal verbs never change their ending.)

Mistake 3: Using "couldn't" to mean "maybe not."
Incorrect: It couldn't rain. (This means it's impossible!)
Correct: It might not rain. (This means maybe it won't rain.)

Summary Checklist

- Use may, might, could for general possibilities (The "Maybe" group).
- Use must when you are almost 100% sure something is true.
- Use can't when you are sure something is impossible.
- Use will/won't for strong predictions about the future.
- Rule: Always use the base form of the verb after a modal (no "-s", no "-ing", no "to").

Quick check

Can you answer these now?

Open each question to check the key ideas from this chapter.

What are modal verbs of possibility?

Modal verbs of possibility, such as may, might, and could, are "helping" verbs used to say that something is "maybe" true or likely to happen.

What is the standard sentence pattern for using modal verbs of possibility?

The pattern is Subject + Modal Verb + Action Word (Base Form).

In modern English, how is might often distinguished from may?

Might is often considered a "weak maybe," used for things that are even less likely to happen than those described with may.

Which modal verbs represent "Low Certainty" (20-50%) on the Certainty Meter?

The modal verbs might, could, and may represent low certainty.

When should you use the modal verb must to express probability?

Use must when you are almost certain (about 90%) because you have strong evidence to support your guess.

What does the modal verb will indicate on the Certainty Meter?

Will indicates very high certainty (99-100%) and is used for facts or very strong predictions.

What is the meaning of may not or might not in a sentence?

These phrases mean "maybe not," indicating that there is a possibility something will not occur.

When should you use can't instead of might not?

Use can't when you are 100% sure that something is impossible.

Which modal verbs are typically used for making suggestions about possibilities?

The modal verbs can or may are often used to suggest possible solutions or actions.

Why is the phrase "It might to rain" grammatically incorrect?

It is incorrect because you should never use "to" after modal verbs like may, might, must, or could.

Do modal verbs change their ending when the subject is he, she, or it?

No, modal verbs never change their ending; you never add "-s" for the third person singular.

What is the difference between saying couldn't and might not?

Couldn't means something is impossible, whereas might not means it is simply possible that it won't happen.

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