Study Notes: Modal Verbs (CEFR Level B1 Grammar)

Hello future grammar expert! This chapter on Modal Verbs is one of the most important parts of B1 English. Don't worry if these verbs seem tricky at first—they are like the 'flavour' or 'attitude' of a sentence. Once you understand them, you will be able to express yourself much more accurately, whether you are giving advice, asking permission, or stating a strong rule!

What Are Modal Verbs? (The Basics)

Modal verbs are special helper verbs that change the meaning of the main verb. They never work alone, and they always tell us about the speaker’s attitude towards the action: ability, possibility, necessity, or advice.

The Golden Rule of Modal Verbs

This rule is vital! Every time you use a modal verb, the main verb that follows must be in its base form (the infinitive without 'to').

MODAL VERB + BASE VERB (V1)

Example: I can run fast. (NOT: I can to run or I can runs)
Example: She must study for the test. (NOT: She must studies)

Did you know? Unlike regular verbs, modal verbs never take an ‘-s’ in the third person singular (He/She/It). They are rebels!

1. Expressing Ability (Can and Could)

We use these modals to talk about skills or capabilities.

A. Can (Present Ability)

Use Can to say someone has the skill or capability to do something right now.

  • Affirmative: I can speak three languages.
  • Negative (Cannot / Can't): He can’t swim yet.
  • Question: Can you help me with this task?
B. Could (Past Ability)

Use Could to talk about an ability someone had in the past (when they were younger, for example).

  • Example: When I was 10, I could run for miles.
  • Example (Negative): Before I took lessons, I couldn’t play the piano at all.

Quick Review: Think of Can as "I am capable now," and Could as "I was capable then."

2. Giving and Asking Permission (Can, Could, May)

When you need to ask if something is allowed, you use a modal verb. The choice depends on how formal you need to be.

A. Can (Informal Permission)

This is the most common and casual way to ask.

  • Asking: Can I borrow your pen?
  • Giving Permission: Yes, you can use it.
B. Could (Polite/Formal Requests)

Using Could makes your request softer and more polite, especially when talking to someone older or in authority.

  • Asking: Could I speak to the manager, please? (More polite than 'Can I speak...')
C. May (Formal Permission)

May is the most formal way to ask for or give permission. It is often used in schools or official settings.

  • Asking: May I leave the room early?
  • Giving Permission: Yes, you may go now.

Memory Tip: Think of the formality ladder:
Informal: Can → Polite: Could → Very Formal: May

3. Expressing Possibility and Probability (May, Might, Could)

These modals tell us how sure we are that something is true or will happen.

A. May and Might (The Maybe Group)

When you are uncertain about something, use May or Might.

  • May: About 50% chance. Example: It may rain later, so take an umbrella.
  • Might: Less than 50% chance (a little more uncertain). Example: We might visit the museum, but it depends on the time.

(For B1, May and Might are often interchangeable, but remember Might usually suggests slightly less certainty.)

B. Could (General Possibility)

Could also expresses possibility, especially when suggesting alternatives.

  • Example: Where is John? He could be stuck in traffic.

Common Mistake: Do not use Can to talk about future possibility.
(X) It can rain tomorrow. (This means it is capable of raining.)
(✓) It may/might rain tomorrow. (This means there is a chance of rain.)

4. Obligation and Necessity (Must, Have to)

These modals tell us that something is necessary or required.

A. Must (Internal/Speaker’s Obligation)

Must expresses an obligation that comes from the speaker, or a very strong personal feeling.

  • Example (Personal feeling): I must remember to call my grandmother tomorrow.
  • Example (Strong instruction/Rule): All students must wear their ID badge.
B. Have to (External Obligation)

Have to (or Has to for He/She/It) expresses an obligation that comes from outside—a rule, a law, or an authority (like the school or the boss).

  • Example (External Rule): We have to arrive by 8:30 am, according to the schedule.
  • Example (Past Obligation): Yesterday, I had to finish my essay before dinner.
C. Prohibition vs. Lack of Necessity (CRITICAL DISTINCTION!)

This is where many students get confused, so read this section carefully!

  1. Mustn't (Must Not): Prohibition

    2. Use Mustn't when something is strictly forbidden or illegal. It means: DO NOT DO IT!

    • Example: You mustn't park here. (It is against the law/rules.)
    • Example: Students mustn’t cheat on exams.
  2. Don't Have To (Lack of Necessity)

    3. Use Don't have to when something is not necessary, but it is okay if you do it anyway.

    • Example: You don’t have to cook dinner tonight; we can order pizza. (It’s optional.)
    • Example: She doesn’t have to attend the meeting if she is busy.

Analogy: Imagine a traffic light.
Mustn’t is a Red Light (Stop! Forbidden!).
Don’t have to is a Flashing Yellow Light (Proceed with caution, but it’s optional).

5. Giving Advice and Suggestions (Should and Ought to)

These modals are used to suggest the best course of action.

A. Should (General Advice)

Should is the most common modal for giving advice or making recommendations. It suggests that something is a good idea.

  • Example: You look tired. You should go to bed early.
  • Example (Negative): You shouldn't worry about small things.
B. Ought to (Similar to Should)

Ought to means exactly the same as Should, but it is less common in modern English. It sounds slightly more formal.

  • Structure Note: Ought is always followed by to.
  • Example: You ought to save more money for university.

Key Takeaway for Advice: Should and Ought to are gentle suggestions. If you want to give a strict order, you must use Must.

Common Mistakes to Avoid

Struggling students often make the same few mistakes with modals. Watch out for these:

1. Adding 'to' after the modal:

  • (X) I must to revise my notes.
  • (✓) I must revise my notes.

2. Adding 's' for He/She/It:

  • (X) She cans pass the exam.
  • (✓) She can pass the exam.

3. Confusing Prohibition and Lack of Necessity:

  • (X) We don’t have to bring our phones into the exam hall. (This sounds like phones are optional.)
  • (✓) We mustn't bring our phones into the exam hall. (This correctly states it is forbidden.)

Quick Review Box: The Main Modals at B1 Level

Modal — Main Function — Example

Can — Ability / Informal Permission — I can cook well. Can I go?
Could — Past Ability / Polite Request — She could swim as a child. Could you wait?
May — Formal Permission / Possibility — May I come in? It may be cold.
Might — Lower Possibility — He might fail the test (but hopefully not).
Must — Strong Obligation / Internal Necessity — You must study harder.
Have to — External Obligation / Rule — I have to wear a uniform.
Should — Advice / Recommendation — You should drink more water.
Mustn’t — Prohibition (Do Not Do) — You mustn't talk during the movie.

Keep practicing these core functions, and you will soon master the art of using modal verbs to communicate precisely and clearly! Good luck!