In English grammar, a modal auxiliary (also known as a modal verb or simply a modal) is a type of auxiliary verb that is used to express modality. Modality refers to the speaker’s attitude, opinion, or degree of certainty about the action or state of the main verb in the sentence. Modal auxiliaries are used to modify the meaning of the main verb, indicating possibility, necessity, ability, permission, willingness, and other related concepts.
The most common modal auxiliaries in English are:
The modal verb ‘Can’
The modal verb can is used to express ability, permission, possibility, or request. It is one of the most commonly used modal verbs in English.
Ability: We use can to talk about someone’s ability to do something.
For example:
I can swim.
She can speak three languages.
They can’t play the piano.
Permission: We use can to ask for permission to do something.
For example:
Can I borrow your pen?
Could I ask a question?
You can go home now.
Possibility: We use can to talk about something that is possible.
For example:
It can rain tomorrow.
I think I can finish this project by the end of the week.
This car can go up to 100 miles per hour.
Request: We can use can to make a polite request.
For example:
Can you help me with this?
Could you please pass the salt?
Would you mind opening the window?
The modal verb can can also be used in the past tense (could) and in the future tense (will be able to).
Past tense. We use could to talk about someone’s ability to do something in the past.
For example:
I could swim when I was a child.
She could speak French, but she forgot it.
They couldn’t play the piano when they were younger.
Future tense. We use will be able to to talk about something that we will be able to do in the future.
For example:
I will be able to drive when I’m 16.
She will be able to speak Spanish fluently by the end of the year.
They will be able to play the piano by the time they’re 10 years old.
Here are some additional rules for using the modal verb can:
Can can be used with both affirmative and negative sentences.
Can can be used with both interrogative and imperative sentences.
Can can be used with both singular and plural subjects.
The modal verb ‘Could’
The modal verb could is used to express possibility, past ability, and polite requests. It is the past tense of can, but it can also be used in the present tense in certain contexts.
Possibility: We use could to talk about something that is possible, but not certain.
For example:
I could be wrong, but I think I saw a UFO.
She could have won the race if she hadn’t tripped.
This car could go up to 100 miles per hour, but I wouldn’t recommend it.
Past ability: We use could to talk about someone’s ability to do something in the past.
For example:
I could swim when I was a child.
She could speak French, but she forgot it.
They couldn’t play the piano when they were younger.
Polite requests: We can use could to make a polite request.
For example:
Could you help me with this?
Could you please pass the salt?
Would you mind opening the window?
Here are some additional rules for using the modal verb could:
Could can be used with both affirmative and negative sentences.
Could can be used with both interrogative and imperative sentences.
Could can be used with both singular and plural subjects.
In addition to the above uses, could can also be used in conditional sentences.
For example:
If I could fly, I would travel the world.
I could have won the race if I hadn’t tripped.
We could go to the movies tonight if you want.
The modal verb ‘May’
May: It expresses possibility, permission, or a wish.
Example: It may rain later.
Possibility: May I use your phone?
Permission: May all your dreams come true.
The modal verb ‘Might’
Similar to “may,” it expresses a lower level of possibility or a more tentative suggestion.
Example: He might arrive late.
Lower level of possibility: I thought we might go to the movies.
The modal verb ‘Must’
Used as an auxiliary to express obligation or compulsion.
Example: You must pay your dues.
In this sense, must does not form a negative. If used with a negative infinitive it indicates obligatory prohibition.
Used as an auxiliary to indicate necessity.
Example: I must go to the bank tomorrow.
Used as an auxiliary to indicate the probable correctness of a statement.
Example: He must be there by now.
Used as an auxiliary to indicate inevitability.
Example: All good things must come to an end.
Used as an auxiliary to express resolution on the part of the speaker when used with I or we, on the part of another or others as imputed to them by the speaker, when used with you, he, she, they, etc.
Used as an auxiliary to express conviction or certainty on the part of the speaker.
Example: He must have reached the town by now, surely you must be joking. Used with an implied verb of motion to express compelling haste.
Example: I must away.
The modal verb ‘Shall’
The modal verb shall is used to express future action, make promises, and express strong determination. It is most commonly used with the first person pronouns I and we.
Future action: We use shall to talk about future action, especially when we are making a promise or expressing strong determination.
For example:
I shall be there on time.
We shall overcome this challenge.
She shall not pass!
Promises: We can use shall to make promises.
For example:
I shall help you with your homework.
We shall never forget you.
She shall have her way.
Strong determination: We can use shall to express strong determination.
For example:
I shall succeed no matter what.
We shall not give up.
She shall not be defeated.
Here are some additional rules for using the modal verb shall:
Shall can only be used with the first person pronouns I and we.
Shall can be used in both affirmative and negative sentences.
Shall can be used in both interrogative and imperative sentences.
Shall is a less common modal verb than will, and its use is often considered to be formal or old-fashioned.
The modal verb ‘Should’
The modal verb should is used to express obligation, necessity, expectation, and advice. It is a more formal modal verb than ought to, and it is often used in writing.
Obligation: We use should to talk about something that we are obligated to do.
For example:
You should always tell the truth.
Students should be respectful of their teachers.
Drivers should obey the speed limit.
Necessity: We use should to talk about something that is necessary.
For example:
You should eat your vegetables.
You should get enough sleep.
You should wear a helmet when you ride a bike.
Expectation: We use should to talk about something that we expect to happen.
For example:
The train should arrive on time.
The sun should be shining tomorrow.
The meeting should start at 10:00 AM.
Advice: We use should to give advice.
For example:
You should see a doctor if you’re feeling sick.
You should save your money for a rainy day.
You should study hard for your exams.
The modal verb ‘Will’
The modal verb will is used to express future action, make promises, and express strong determination. It is one of the most commonly used modal verbs in English.
Future action: We use will to talk about future action, especially when we are making a promise or expressing strong determination.
For example:
I will be there on time.
We will overcome this challenge.
She will not pass!
Promises: We can use will to make promises.
For example:
I will help you with your homework.
We will never forget you.
She will have her way.
Strong determination: We can use will to express strong determination.
For example:
I will succeed no matter what.
We will not give up.
She will not be defeated.
The modal verb ‘Would’
The modal verb would is a versatile word in English that is used to express various meanings and functions. It is commonly used to indicate the past tense of will, but it has other important uses as well. Here are the main meanings and usages of would:
Past of Will: As the past tense of will, would is used to express actions that were planned or promised in the past or to talk about future events seen from a past perspective.
Example:
He said he would come to the party. (Past perspective: He made the promise to come in the past.)
Polite Requests and Offers: Would is frequently used to make polite requests and offers, as it softens the tone of the sentence.
Example:
Would you please pass me the salt?
Would you like a cup of tea?
Hypothetical or Unreal Situations: Would is used to express hypothetical or unreal situations, often in conditional sentences.
Example:
If I were rich, I would buy a mansion. (Hypothetical situation; I am not currently rich.)
She would travel the world if she had enough money. (Unreal situation; she doesn’t have enough money to travel right now.)
Past Habits and Repeated Actions: Would can be used to talk about past habits or actions that were repeated in the past.
Example:
When I was a child, I would play with my toys for hours. (Past habit of playing with toys.)
Reported Speech: In reported speech, would can be used to indicate indirect speech for statements originally expressed with will.
Example:
Direct speech: She said, “I will be there.”
Reported speech: She said that she would be there.
Willingness in the Past: Would can indicate willingness or desire in the past.
Example:
I would always help my friends when they needed me. (I was always willing to help.)
Remember that the usage of would can sometimes be interchangeable with could or might, depending on the context. It’s essential to consider the overall meaning and intention of the sentence when using would in different situations.