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5.4: Grammar Presentation-Modals

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    Modal auxiliaries are helping verbs that are used only with a main verb to help express mood.

    The following is the basic formula for using a modal auxiliary:

    Positive statements: Subject + modal auxiliary + base verb.

    Example positive statement: James may call.

    Yes or no question: Modal auxiliary + subject + base verb?

    Example yes or no question: Should I drive?

    There are eight main modal auxiliaries in English.

    Modal Auxiliary

    Use

    Modal Auxiliary + Main Verb

    can

    Expresses an ability;

    possibility;

    or a polite request.

    I can lift this forty-pound box. (ability)

    We can embrace green sources of energy. (possibility)

    Can you give me a piece of paper? (polite request)

    could

    Expresses an ability in the past;

    a present possibility/suggestion;

    a past or future permission;

    or a polite request.

    I could beat you at chess when we were kids. (past ability)

    We could bake a pie! (present possibility/suggestion)

    Could we pick some flowers from the garden? (future permission)

    Could you pass the handout to me? (polite request)

    may

    Expresses uncertain future action;

    permission;

    or a polite request.

    I may attend the concert. (uncertain future action)

    You may begin the exam. (permission)

    May I attend the concert (polite request)

    might

    Expresses uncertain action

    I might attend the concert (uncertain action)

    should

    Expresses obligation;

    expectation;

    or advisability.

    I should mail my RSVP. (obligation)

    She should be passing all her classes. (expectation)

    Should I call my mother? (advisability)

    will

    Expresses intended future action;

    ask a favor;

    ask for information

    I will get an A in this class. (intended future action)

    Will you buy me some chocolate? (favor)

    Will you be finished soon? (information)

    would

    States a preference/request;

    polite request;

    explain an action;

    introduce habitual past actions

    I would like the steak, please. (preference/request)

    Would you please move the books? (polite request)

    I would go with you if I didn't have to babysit tonight. (explain an action)

    He would write to me every week when we were dating. (habitual past action)

    must

    Expresses obligation;

    or an inference.

    We must be on time for class. (obligation)

    He must be sick. (inference)
    Table 14 English Modals

    “Table 14 English Modals” is derived from “Writing for Success” by Lynne Bost, Barbara Hall, Michelle Kassorla, Karen McKinney-Holley, Kirk Swenson, and Rebecca Weaver licensed under CC BY.

    2.1.4.1. Possibility and Inference

    We can express certainty with modals of possibility. If you are 100% certain, then no modal is necessary, but if you’re almost certain then use the modal must. If you’re less than 50% certain, then use may, might, or could.

    When your teacher is absent, you might infer these possibilities:

    She is sick. (100% certain)

    She must be sick. (95% certain)

    She may be sick. (less than 50% certain)

    She might be sick. (less than 50% certain)

    She could be sick. (less than 50% certain)

    For more information on this topic, watch these videos: Modals of Possibility- May, Might, and Could and Modal of Certainty-Present

    2.1.4.1.1. Exercise 3-Inference Practice

    Below is a list of situations. Give one sentence with must for a strong inference (guess), and write another sentence with a less likely possibility. Use the example to guide you.

    Example: Your teacher’s eyes are red.

    95% certain: She must have allergies.

    Less than 50% certain: She might be high on drugs.

    1. A restaurant is busy.
    2. Your classmate is using crutches.
    3. You see a dog at your friend’s house.
    4. Your classmate is sad after receiving her exam results.
    5. Your classmate is coughing.
    6. Your friend is wearing a sun hat and swim suit.
    7. Your stomach is making noises.
    8. You hear an ambulance.
    9. You received a high grade on your homework.
    10. You see your family member at the train station.

    2.1.4.2. Polite Requests

    Could, would, and may are equally polite when making a request. However, can is less formal but still polite. Can is used with someone you are familiar with or close to. May is used when asking permission or a request, so the subject of the request is “I”; the other modals can be used with any subject. Although all these modals are polite, it is still recommended to use please with these modals. See the examples below.

    1. May I (please) have a cup of water (please)?
    2. Could I (please) have a cup of water (please)?
    3. Can I (please) have a cup of water (please)?
    4. Would you (please) give me a cup of water (please)?
    5. Could you (please) give me a cup of water (please)?
    6. Can you (please) give me a cup of water (please)?
    7. Would you mind giving me a cup of water (please)?

    For more information on this topic, watch these videos: Modal Verbs used for asking Permission and Making Requests and Modal Verbs: Making Requests

    2.1.4.2.1. Exercise 4-Polite Requests

    Look at the following situations and write how you would politely request what is needed.

    1. You are emailing your instructor. You want to make an appointment to review the exam results.
    2. You want to schedule time off from work so that you can visit your family in another city. You will ask your supervisor.
    3. You are at the doctor’s office waiting room. You have been waiting for a while and need to leave soon. The receptionist is available to ask about the wait time.
    4. You want to use your brother’s car since yours broke down.
    5. You are with your classmate and want to use her phone to call your mom to pick you up.

    2.1.4.3. Advisability, Expectations, Obligation, and Necessity

    Should can be used to give advice, expectations, and obligations. However, when stating a strong necessity, use must or have to.

    1. You should drink hot water with honey. (advice)
    2. You should be finished with your reading by now. (expectation)
    3. I should be at work at 9AM. (obligation)
    4. I must be a work at 9AM. (necessity)
    5. I have to be at work at 9AM. (necessity)

    For more information on this topic, watch these videos: Need to, Have to, & Must: Necessity and Modals for Advice: Should & Should Not

    2.1.4.3.1. Exercise 5-Should or Must

    Complete the sentences with either should or must. Both answers are possible, but the meaning is different. Use the most appropriate word for the intended meaning.

    1. According to my counselor, I ____________ take 12 more units to graduate.

      a. should

      b. must

    2. According to my counselor, I ____________ meet with a tutor to improve my writing.

      a. should

      b. must

    3. We ____________ eat healthy.

      a. should

      b. must

    4. Plants ____________ have sun in order to live.

      a. should

      b. must

    5. You ____________ submit your homework in order to receive credit.

      a. should

      b. must

    2.1.4.4. Modals Expressing Past Tense

    Used to, would, and could can be used to express past situations that are no longer true in the present time. Look at the examples.

    1. I used to travel to many countries. (past habitual action)
    2. I would visit new and exciting places. (past habitual action)
    3. I could handle the long flights with no problems. (past ability)
    4. I had to save my money to buy my plane tickets. (past necessity)

    Examples 1 and 2 show that an action occurred regularly, but it no longer happens today. In the third example, could signals an ability I once had, but I no longer have. The last example shows past necessity with had to.

    For more information on this topic, watch this video: Past Modals and Difference Between Used to and Would

    2.1.4.4.1. Exercise 6-Listening Practice

    Listen to Rachel talk about her childhood. Mark the sentences below as true or false. Follow this link for the listening.

    1. Rachel lives on a farm now.

      a. True

      b. False

    2. She hung out with her friends on the weekends.

      a. True

      b. False

    3. She had the ability to lift heavy items.

      a. True

      b. False

    4. She didn’t need to work on the farm if the weather was bad.

      a. True

      b. False

    2.1.4.5. Modals Expressing Regrets and Criticism

    Sometimes we regret past actions or inactions. Sometimes we criticize others for their past actions or inactions. Modal help express regrets and criticism. Look at the examples.

    1. I did not wear a jacket. Now it’s cold. I should have brought a jacket. (regret)
    2. I ate a lot of chocolate. Now my stomach hurts. I should not have eaten all the chocolate. (regret)
    3. You are late. You did not tell me. You might have called me to say you were late. (criticism)
    4. You didn’t keep my secret. You could have kept my secret! (criticism)

    Let’s look at the formation of regrets and criticism.

    Regret: Subject + should/should not + have + past participle.

    Criticism: Subject + might/could + have + past participle.

    Contractions: Subject + should’ve/shouldn’t have/might’ve/could’ve + past participle.

    For more information on this topic, watch this video: Using Perfect Modals to Express Regrets-English Grammar

    2.1.4.5.1. Exercise 7-Expressing Regret and Criticism

    Rewrite the sentences with the correct form for the modal in parentheses. Your sentences might be affirmative or negative. Use the example to guide you.

    Example: I told Jennifer my secret. She talks a lot.

    (Should) I shouldn’t have told Jennifer my secret.

    Example 2: I didn’t do my homework.

    (Should ) I should have done my homework.

    1. I have spinach in my teeth. You didn’t tell me!

      (Might)

    2. The electricity bill is late. You sent the payment through the mail.

      (Could)

    3. I made a lot of food for dinner. Now, I have a lot of leftovers.

      (Should)

    4. I didn’t bring an umbrella to class. The forecast predicted heavy rain.

      (Should)

    5. Maria waited to sign up for Political Science. Now the only instructor available has bad reviews.

      (Might)

    6. Huy’s car broke down. He was absent for class and missed an important exam. His teacher won’t let him make it up.

      (Could)

    2.1.4.5.2. Exercise 8-What a Mess!

    Look at the picture of Yvonne’s room. What a mess! Create 5 sentences criticizing here. What should/could/might she have done? Use the example to guide you.

    Example: Yvonne could have put her computer on her desk.

    Image 14 What a Mess!

    2.1.4.5.3. Exercise 9-Should Present vs Past Tense

    Read the sentences that include should. Select whether should is expressing advisability in the present or past.

    1. You should wear a jacket to the performance tonight.

      a. present

      b. past

    2. Latif should have driven slower.

      a. present

      b. past

    3. He should have managed his time better. Now, he’s suffering the consequences.

      a. present

      b. past

    4. Brandi should open a new salon to accommodate all her beautiful clients.

      a. present

      b. past

    5. Bridget should take time to relax.

      a. present

      b. past

    6. Rylee should have attended the planning meeting. Now her club wants to exclude her from the event.

      a. present

      b. past

    7. Grades should be entered no later than the Monday after the end of the semester.

      a. present

      b. past

    8. Nancy should retire soon so that she can spend time with her grandson.

      a. present

      b. past

    9. Abigale should have followed her teacher’s directions.

      a. present

      b. past

    10. Ricardo should have worked in the garden before it started raining. Now he has a cold.

      a. present

      b. past

    2.1.4.5.4. Exercise 10-Listening Practice for Regrets and Criticism

    The weekend flew by! Listen to Rachel talk about her regrets. Follow this link for the listening.

    1. Select the activities she did.

      a. do homework

      b. call Grandma Betty

      c. call Kathy

      d. buy groceries

      e. clean the house

      f. watch the new series on Netflix

      g. do laundry

      h. go to Asha’s house

    2.1.4.6. Common Errors

    Be aware of these four common errors when using modal auxiliaries:

    Using an infinitive instead of a base verb after a modal
    Incorrect: I can to move this heavy table.
    Correct: I can move this heavy table.

    Using a gerund instead of a base verb after a modal
    Incorrect: I could moving to the United States.
    Correct: I could move to the United States.

    Using two modals in a row
    Incorrect: I should must renew my passport.
    Correct: I must renew my passport.
    Correct: I should renew my passport.

    Leaving out a modal
    Incorrect: I renew my passport.
    Correct: I must renew my passport.

    “Common Errors” is derived from “Writing for Success” by Lynne Bost, Barbara Hall, Michelle Kassorla, Karen McKinney-Holley, Kirk Swenson, and Rebecca Weaver licensed under CC BY.

    2.1.4.6.1. Exercise 11-Common Modal Auxiliary Errors

    The sentences have errors related to modal auxiliaries. Identify and correct the errors.

    1. She should to make dinner for her family every night.
    2. He must drives his mother to the store tonight
    3. It might raining in New York now.
    4. I could played baseball every day when I was a boy.
    5. I would ate dinner with my mother and father every day.
    6. The girl has play with her friends after school tomorrow.
    7. He musts goes to the doctor for the cut on his head.
    8. Children should not be play with matches.
    9. My big brother could ate a lot of food when he were a boy.
    10. He might not sees the spider on his shirt.
    11. I could be played football when I was a young man.
    12. It may raining tonight.
    13. His sister must goes to school every day next week.
    14. The boys and their father would worked on the farm all day when they was younger.
    15. We had to do a lot of homework tomorrow evening.
    16. He have to finishes his homework before he can goes to the party with his friends.
    17. He must finishes his composition before he cans goes outside to play.
    18. He must always eats all the food on his plate before he can leaves the table.

    “Common Modal Auxiliary Errors” is derived from “Modal Verb Form Errors Analysis and Structure Exercise” by Don Bissonnette under CC BY-NC.

    This page titled 5.4: Grammar Presentation-Modals is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Rebecca Al Haider via source content that was edited to the style and standards of the LibreTexts platform.