Auxiliary and Modal Verbs

The world might head towards a water crisis. The world will head towards a water crisis. Both of these sentences are talking about the same world and a water crisis. However, the former indicates a weak possibility whereas the latter almost declares it. Interestingly, this happens just because of a change in one word known as the modal verbs.

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Auxiliary and Modal Verbs

By now you might have an idea of what the auxiliary and modal verbs are used for. If not, you will by the end of this. Auxiliary verbs are the helping verbs used in sentences along with the verbs to set the mood, tense, tone etc. of the sentence.

Thus if you use the auxiliary ‘might’, it indicates a slight probability. But if you use the auxiliary ‘will’, it indicates a strong affirmation. We further divide the auxiliaries into two types- primary auxiliaries and modal auxiliaries.

Primary Auxiliaries

The words “be”, “have” and “do” are called primary auxiliaries. These are known as primary because they are the most frequently occurring auxiliaries and are used in their different forms in the English language.

Evidently, the forms of “be” are “is”, “am”, “are”, “was” and “were”. The forms of “have” are “have”, “has” and “had”. Lastly, the forms of “do” are “do”, “does” and “did”.

Using Primary Auxiliaries

1] Be

The forms of “be” are:

  • Present tense: is, am, are
  • Past tense: was, were
  • Past participle: been

i) To form continuous tense:

  • He is reading a book.
  • we were reading a book.
  • He has been reading a book.

ii) For passive voice:

  • The work is done.
  • The work is being done.

iii) To express a previous plan or  agreement:

  • You were to visit the doctor.
  • I am to go to Meerut.

iv) To express a command:

  • You are to get the work done by tonight.
  • The plumber is to repair the pipeline tomorrow.

v) To express feelings, age, size, weight, price, time etc. :

  • Today is a warm day.
  • I am not happy.
  • My weight is 50 kgs.

2] Have

The forms of “have” are:

  • Present tense: has, have
  • Past tense: had
  • Past participle: had

i) To form perfect tense:

  • He has read the book.
  • We had done our household chores.

ii) To form passive voice:

  • The work has been done.
  • The room had been cleaned.

iii) To express a compulsion:

  • He had to go.
  • You have to obey the law.

iv) To express a job got to be done:

  • I have my room cleaned every week.
  • She has bread and butter for breakfast.

v) To express the consumption of food, drinks, events etc.

  • I have tea in the morning.
  • He had the party at his house.
  • You have a test tomorrow.

3] Do

The forms of “do” are:

  • Present tense: do
  • Past tense: did
  • Past participle: done

i) In additions to avoid repetition of verbs:

  • He likes to read and so do I.
  • You liked to dance and so did she.

ii) In question tags and short answers:

  • You liked the film; didn’t you?
  • Yes, I did.

iii) To form interrogative and negative forms of present and past indefinite tenses and imperatives:

  • Do not lean over the fence.
  • He does not work. Does he?

iv) To stress some action in the present and past indefinite tenses and in imperatives:

  • I do go to the class every day.
  • I did the work daily.
  • Do finish the work for me.

Modal Auxiliaries/ Modal Verbs

Image result for modal verbs

The commonly used modal auxiliaries, also known as modal verbs, are as follows:

Can and Could

  • Can’ states ability: I can walk to the hotel.
  • It also indicates permission: You can go to the party tonight.
  • ‘Could’ is used for a request: Could I go to the party tonight?
  • It is used as the past tense of can in indirect speech: You said you could help me.
  • Could is used to indicate ability in the past; He could dance well when I last met him.

May and Might

  • May is used to ask for permission: May I come in?
  • It is used to express a wish: May you have a good life ahead.
  • We can also use ‘may’ to express possibility: There may be some hope.
  • May’ indicates a weak possibility whereas ‘might’ indicates a weaker possibility: I may come today. OR She might come tomorrow.

Shall, Should, Will, Would

i) Shall is used in the first person and will in the second and third person:

  • I shall not come today.
  • You will work for me.
  • He will not listen to you.

ii) We can also use shall in second or third person to express a threat, command or a promise:

  • You shall be awarded suitably.
  • He shall never show up here again.

iii) Shall can also be used in the first person to indicate an offer or suggestion:

  • Shall I accompany you?

iv) Will is used to express a decision:

  • I will not come today.

v) It can also be used to indicate a habit:

  • He will drink a cup of coffee as usual.

vi) We can also use will for an invitation:

  • Will you attend my cousin’s wedding?

vii) In clauses that start with if, ‘should’ is used to express a probable event:

  • If it should rain, the match will be called off.

Must and Ought

  • Must’ is a modal verb that can be used to express necessity: You must come tonight.
  • We can also use ‘must’ to express fixed determination: I must have an opportunity to do what I wish.
  • Ought can express certainty: We ought to win this.


  • It can indicate a discontinued habit: I used to go to the gym every evening.


  • Need’ can be used to denote certainty: We need to win this.
  • We can also use need to denote requirement: I need you to stay.


  • Dare is a modal verb that indicates strong ability or being bold enough: How dare you argue with me?
  • We can also use dare to strike a challenge: I dare you to cross the bridge in 30 seconds.

Solved Example For You

Q: Fill in the blanks:

  1. You ___ not lie. (should/could)
  2. We ___ to help those in distress. (need/ought)
  3. I am glad she ___ come yesterday. (could/would)
  4. I am late for the office. I ___ take a cab. (must/may)


  1. should
  2. ought
  3. could
  4. must
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