Could, Would, Should: Modal Verbs in English

Mr. Jack
Jan 25, 2024
4 min read

In English, modal verbs are auxiliary (additional) verbs that modify (change) the mood or mode of the verb they accompany.

They are essential in expressing abilities, possibilities, obligations, and permissions.

The sentence structure for modal verb usage in English typically follows this pattern:

Subject + Modal Verb + Base Verb + (Object/Complement)

Here's a breakdown of each component:

Subject: This is the person, place, thing, or idea that is performing the action or being described. Examples include "I", "She", "The cat", etc.
Modal Verb: These are the auxiliary verbs that express necessity, possibility, permission, or ability. Examples include "can", "might", "should", etc. Remember, modal verbs are used in their base form and do not change according to the subject.
Base Verb: This is the main verb that follows the modal verb. It is always in its base form (the infinitive without "to"). For example, "go", "be", "take", etc.
Object/Complement: This part of the sentence is optional and depends on the verb being used. It completes the action of the verb or adds more information. For instance, in the sentence "She can play the piano", "the piano" is the object.

Here are some examples to illustrate the structure:

I can swim. (Subject: "I", Modal Verb: "can", Base Verb: "swim")
You should try the cake. (Subject: "You", Modal Verb: "should", Base Verb: "try", Object: "the cake")
He might go to the party. (Subject: "He", Modal Verb: "might", Base Verb: "go", Complement: "to the party")

Remember, questions with modal verbs follow a slightly different structure, where the modal verb comes before the subject:

Can you help me? (Modal Verb: "Can", Subject: "you", Base Verb: "help", Object: "me")

What are Modal Verbs?

Modal verbs are special verbs that are used to express necessity, possibility, permission, or ability. They do not change their form according to the subject and are always followed by a base form of a verb (the infinitive without 'to').

The primary modal verbs in English are: can, could, may, might, shall, should, will, would, and must.

1. Can and Could

"Can" is used to express ability or possibility. "Could" is its past tense form but is also used in present tense to express a more polite or less certain action.

Ability: "I can speak three languages fluently."
Possibility: "It can rain in the evenings here."
Polite Request: "Could you please open the window?"

2. May and Might

"May" and "might" are used to express possibility. "Might" is generally considered a bit more uncertain than "may."

Permission: "May I leave the table?"
Possibility: "She might come to the party if she finishes work early."

3. Shall and Should

"Shall" is often used in questions to offer or suggest something, while "should" is used to give advice or talk about what is right or correct.

Offer/Suggestion: "Shall we go to the cinema tonight?"
Obligation/Advice: "You should eat more vegetables."

4. Will and Would

"Will" is used for future intentions or promises. "Would" is the past tense of "will" but also used for polite requests or hypothetical situations.

Future Intentions: "I will call you tomorrow."
Polite Request: "Would you like some coffee?"
Hypothetical Situations: "I would travel more if I had more time."

5. Must

"Must" is used to express obligation, necessity, or strong recommendation.

Obligation/Necessity: "You must stop at a red light."
Strong Recommendation: "You must visit the new museum exhibit."

Important Points to Remember

Modal verbs do not change form based on the subject (e.g., "I can," "he can").
They are followed directly by the base form of the verb ("He must go," not "He must to go").
There is no "-s" on the third person singular form in the present tense ("She can," not "She cans").
Questions are formed without 'do/does/did' ("Can you help me?" not "Do you can help me?").

Common Mistakes to Avoid

Mixing up "can" and "could" in terms of certainty. Use "can" when sure, and "could" for possibilities.
Using "will" for polite requests. Use "would" instead to sound more polite.
Confusing "must" with "have to". "Must" is for personal obligations, while "have to" is for external obligations.

Conclusion

Mastering modal verbs is a step towards achieving fluency in English. Remember, the best way to learn is through practice and exposure. Try incorporating these verbs into your daily conversations and writing. As you become more familiar with their usage, you'll find expressing nuances such as possibility, ability, and necessity becomes second nature.

Use the table below and have a go at the exercise. Happy learning!

Fill in the blanks with the correct modal verb from the options provided. (Suggested answers are below.)

You _______ be tired after such a long journey. (must / might / can)
She _______ speak Spanish when she was younger but she's forgotten now. (could / will / should)
_______ I borrow your pen for a moment? (May / Will / Must)
He's not here right now. He _______ have gone to the store. (must / can / might)
You _______ not enter the lab without permission. (must / could / shall)
We _______ visit our grandparents this weekend. (should / could / will)
_______ you please pass me the salt? (Can /Should/Will)
I _______ drive a car when I was only sixteen. (might / could / would)
They _______ come to the party if they finish work early. (might / must / would)
Tomorrow, we _______ meet at 3 PM. (will / might / could)