GRAMMAR: MODAL AUXILIARIES

 Modal Auxiliary: Definition, Types, Rules & Examples

What is a Modal Auxiliary?

A Modal Auxiliary is a helping verb that expresses the mood, attitude, ability, possibility, permission, obligation, necessity, advice, or probability of the action performed by the main verb.

Modal auxiliaries are always used with the base form (V1) of the main verb.

Examples:

• She can swim.
• You must wear a seat belt.
• We should respect our teachers.

Types of Modal Auxiliaries

The common modal auxiliaries are:

• Can
• Could
• May
• Might
• Shall
• Should
• Will
• Would
• Must
• Ought to
• Need
• Dare
• Used to

Rules of Modal Auxiliaries

Rule 1

A modal auxiliary is always followed by the base form (V1) of the main verb.

✅ She can sing.

❌ She can sings.

Rule 2

Modal auxiliaries do not change according to the subject.

✅ I can swim.

✅ She can swim.

✅ They can swim.

Rule 3

Two modal auxiliaries are generally not used together.

❌ He will can come.

✅ He will be able to come.

Rule 4

Modal auxiliaries do not take -s, -es, -ing, or -ed forms.

✅ She may help us.

❌ She mays help us.

Examples

Modal	Function	Example
Can	Ability	She can drive a car.
Could	Past Ability	He could run fast when he was young.
May	Permission	May I come in?
Might	Possibility	It might rain today.
Shall	Suggestion	Shall we start?
Should	Advice	You should study regularly.
Will	Future	I will call you tomorrow.
Would	Polite Request	Would you help me?
Must	Obligation	You must obey the law.
Ought to	Moral Duty	We ought to respect our elders.

Time to Revise

Modal Auxiliary = Helping Verb + Base Form (V1)

It expresses:

• Ability
• Permission
• Possibility 

• Obligation
• Advice
• Necessity
• Probability

Coming Next

In the next blog, we will learn the Uses of Each Modal Auxiliary and practice exercises.

Modal Auxiliaries – Practice Questions

Class 11 & 12 English Grammar |

A. Fill in the blanks with suitable modal auxiliaries.

1. You ______ always speak the truth.

2. ______ I borrow your notebook?

3. She ______ solve this difficult problem.

4. We ______ plant more trees to protect the environment.

5. It ______ rain heavily this evening.

6. Students ______ complete the assignment before Monday.

7. You ______ smoke in the hospital.

8. They ______ visit us during the holidays.

9. ______ you please pass me the salt?

10. I ______ finish this work today.

B. Choose the Correct Modal Auxiliary.

1. You ______ wear a seat belt while driving.

   a) might

   b) must

   c) could

   d) may

2. ______ I use your mobile phone?

   a) Shall

   b) May

   c) Must

   d) Ought to

3. He ______ run very fast when he was a child.

   a) could

   b) may

   c) will

   d) shall

4. We ______ help people in need.

   a) should

   b) might

   c) could

   d) may

5. It ______ snow tonight.

   a) might

   b) ought to

   c) must

   d) should

C. Rewrite the Sentences Using a Suitable Modal Auxiliary.

1. It is necessary to obey traffic rules.

2. It is possible that she will come tomorrow.

3. I request you to help me.

4. It is your duty to respect your parents.

5. He has the ability to solve this puzzle.

D. Spot the Error and Correct It.

1. She can sings beautifully.

2. He must goes now.

3. They should to complete the project.

4. I can to swim.

5. May you help me?

E. Write Your Own Sentences.

Write one sentence each using:

- Can

- Could

- May

- Must

- Should

⭐ Remember:

A modal auxiliary is always followed by the base form (V1) of the main verb.

Correct: She can sing.

Incorrect: She can sings.

NOTE: Will provide answer key soon with explanation! Till then practice this questions! Happy Learning ❤️ 

Modal Auxiliaries – Answer Key

Class 11 & 12 English Grammar |

A. Fill in the Blanks

1. You should always speak the truth.

2. May I borrow your notebook?

3. She can solve this difficult problem.

4. We should plant more trees to protect the environment.

5. It might rain heavily this evening.

6. Students must complete the assignment before Monday.

7. You must not smoke in the hospital.

8. They may visit us during the holidays.

9. Could you please pass me the salt?

10. I must finish this work today.

B. Choose the Correct Modal Auxiliary

1. You must wear a seat belt while driving.

   ✅ Answer: (b) must

2. May I use your mobile phone?

   ✅ Answer: (b) May

3. He could run very fast when he was a child.

   ✅ Answer: (a) could

4. We should help people in need.

   ✅ Answer: (a) should

5. It might snow tonight.

   ✅ Answer: (a) might

C. Rewrite the Sentences

1. It is necessary to obey traffic rules.

   → You must obey traffic rules.

2. It is possible that she will come tomorrow.

   → She may come tomorrow.

3. I request you to help me.

   → Could you help me, please?

4. It is your duty to respect your parents.

   → You ought to respect your parents.

5. He has the ability to solve this puzzle.

   → He can solve this puzzle.

D. Spot the Error and Correct It

1. ❌ She can sings beautifully.

   ✅ She can sing beautifully.

2. ❌ He must goes now.

   ✅ He must go now.

3. ❌ They should to complete the project.

   ✅ They should complete the project.

4. ❌ I can to swim.

   ✅ I can swim.

5. ❌ May you help me?

   ✅ Could you help me? (or Can you help me?)

E. Sample Answers

Can: I can solve difficult sums.

Could: Could you lend me your book?

May: May I come in, Sir?

Must: We must follow traffic rules.

Should: Students should revise their lessons every day.