Difference Between Can and May

Introduction

There is no doubt that school time is the best and the most memorable time of our lives. There is no burden, no responsibility, and no tension about the future. Remember the time when we were nagged by our teachers for using “can” instead of “may” while asking for permission to enter the classroom. It is a myth that “can” and “may” have a slight difference between them. Though sometimes these words are used interchangeably, however, both possess different meanings and create a different impact when used in a sentence. The use depends on what context we are trying to express in that sentence. Let us take it this way:

“Can I enter the class?”

“May I enter the class?”

In the above example, the intention is the same in both sentences, i.e., to ask permission to enter. But, the use of “may” represents the permission to ask someone who is in higher authority than us. “May” denotes a “formal expression.”

“Can” and “May” are “modal verbs” or we can say “helping verbs.” Modal verbs are used to show expressions like any obligation, permission, ability, possibility, necessity, certainty, or suggestion to any sentence. They come before the main verbs and do not change according to the number of subjects in a sentence.

Can vs May

The key difference between “Can” and “May” depends upon the way they are to be used. The modal verb “May” is used in situations where permission is requested or given, in a formal manner. It is also used to refer to the possibility of an event occurring. The use of “May” also expresses any wish or desire. Example:

1. May I use the restroom? (Denotes request permission)
2. She may leave the house if she wants to. (Denotes giving permission)
3. It may rain today. (Denotes possibility of occurring of an event)
4. May God bless you. (Denotes a wish)

The use of the modal verb “Can” is also done to request or give permission but in an informal way. It is also used to denote an opportunity, ability, offer, or possibility of occurrence of a certain event. Example:

1. You can stay here if you want to. (Denotes giving permission)
2. Can I borrow your pen? (Denotes request permission)
3. She can sing a song. (Denotes the ability of a person)
4. I am free on Sunday so we can go to an amusement park. (Denotes opportunity
5. They can attend the concert provided they reach the venue on time. (Denotes the possibility)
6. Can I go out with you to buy the vegetables? (Denotes an offer)

Difference Between Can and May in Tabular Form

Parameters of Comparison	Can	May
Meaning	The modal verb “Can” is used to express opportunity, capability, permission, possibility, and offer.	The modal verb “May” is used to express the permission and possibility of an event. Any wish or desire is also expressed.
Nature	It is informal.	It is formal.
Permission	Sentences including “Can’ signifies, taking permission but in an unofficial manner.	Sentences including “May” signifies, taking permission to do something but in an official manner.
Use	“Can” is used in the corresponding interrogative and negative sentences. Its use always comes up with a condition.	“May” is used in expressing any possibility in an affirmative sentence.
Significance in Negation	When “Can not” (negation) is used in a sentence, it denotes impossibility.	When ‘May not” (negation) is used in a sentence, it denotes improbability. However, it is to be noted that “May” is rarely used in a negative form.
Past form	The past form of “Can” is “Could.”	The past form of “May’ is “Might.”
What the past form represents	“Could” represents the possibility of happening of an event, however, there is uncertainty or weak possibility for that event to occur.	“Might” represents the lower probability of an action taking place.
Examples	I cannot go to the concert tomorrow. (Impossibility)Can I borrow your pen? (Interrogative and Permission)I could have completed my work by yesterday if I was not too tired. (Possibility)I can help you in solving the question. (Offer)	I may not come today. (Improbability)It may rain tomorrow. (Possibility)Kriti thought that I might be at home. (Possibility)May all his wishes come true.

What is “Can”?

“Can” belong to the family of modal verbs. It denotes any type of possibility, ability, permission, opportunity, or offer. 

Properties of “Can”

• “Can”as a modal verb is used to refer to an action of present as well as future.
• It can never be conjugated according to the subject matter of a sentence.
• “Can” is also used in an interrogative and negative sentences.
• All modal verbs are put before the verb and are used only once in a sentence.

Uses of “Can”

 “Can” is the most common modal used while speaking or writing English. It denotes:

• The possibility of an action taking place

Example: Smriti can submit the assignment by tomorrow.

In the above sentence, “Can” is used to show the possible chances of Smriti completing her assignment. It is not certain but there exist favorable chances of the completion of the work (action) within the given period.

• The ability or capability of a certain person

Example: She can play guitar quite well.

The above sentence shows a person’s ability to play a musical instrument.

• Requesting or permitting to do a certain action

Example: Rohan said to her, “Can I have pizza today?”

She replied, “Yes, you can.”

In the above sentences, permission is requested as well as granted. The use of “Can” in the former sentence represents the request for a certain action and in the latter one, the permission to do that action is granted.

• Any opportunity depicted through the sentence.

Example: As Vaibhav has no work to do, he can meet his friends today.

In the above sentence, an opportunity is shown. There is a strong possibility of Vaibhav meeting his friends as he is free.

• Any offer made

Example: Can I help you in completing the assignment?

In the above sentence, an offer to help is made by one person to another.

Note: The use of ‘Can” is also done in a sentence stating any truth or general fact. Example:

High Cholesterol can lead to heart disease.

Eating too many chocolates can cause cavities.

Different Forms in Which “Can” is Used

• Affirmative Form

Affirmative means “Positive.” Sentences that are declaratory and do not include negative words are affirmative in form.

1. He can walk faster than I.
2. I can play chess.
3. We can go for a morning walk.
4. I can go to school by bicycle.
5. She can do better in exams if she studies well.

(Th use of “can” in the above sentence is conditional.)

• Negative Form

The use of negative words like “no, not, never, or nothing,” makes a sentence negative in form.

1. She cannot do Mathematics properly.
2. I cannot eat Mangoes because I am allergic to them.
3. Shweta cannot write fast.
4. It cannot be true.
5. I cannot believe that he cheated in an exam.

• Interrogative Form

A sentence in which a question is asked is the interrogative form. These sentences always end with a question mark (?).

1. Can I go shopping today?
2. Can you lend me your phone?
3. Can’t you travel alone?
4. Can I leave the class now?
5. Can he lift this box?

Could – Past Form of “Can”

The past form of “Can” is “Could.” They both denote the same expressions.

• Requesting somebody to do something for you

Could you buy me a packet of chips?

• Possibility of an action to take place

I could have left the bus if I did not reach the stop on time.

• Giving suggestion

You could do your homework tomorrow and take a rest today.

The difference between “Can” and “Could” is that where “Can” shows a strong possibility of an action taking place, “Could” shows a weaker possibility of an event occurring.

What is “May”?

“May” belongs to the family of modal verbs. It is used to refer to any possibility or permission.

Properties of “May”

• “May” as a modal verb is used to refer to an action of past, present as well as future tense.
• It is never conjugated according to the subject matter of a sentence.
• “May” is used in an interrogative form but rarely used in a negative form
• “May” is also used to express any wish or desire.
• All modal verbs are placed before the verb and used only once.

Uses of “May”

• Possibility of an action to take place

Example: Jimin may leave India to complete his further studies.

In the above sentence, the possibility of Jimin leaving the country is shown. The possibility is not certain.

• Requesting or asking permission to do a certain action.

Example: “May I use the restroom?”

“Yes, you may.”

In the above sentences, permission is asked as well as granted. The use of “May” depicts the formal nature and a polite tone.

• Express any wish or desire

Example: May you have a great year ahead.

Different forms in which “May” is used

• Affirmative Sentence

“May’ is used mostly in affirmative sentences. It refers to a declaration of a fact.

1. She may be promoted for her hard work.
2. I may complete the school project within 2 days.
3. It may be sunny tomorrow.
4. He may come home by 7 PM.
5. Jayant may be tired due to lack of sleep.

• Negative Sentence

“May not” is rarely used. Instead of “May not,” “cannot” is preferred.

1. She may not be ready for the marriage.
2. I may not have dinner as I am full.
3. Shruti may not stay in my house.
4. You may not spend your savings unnecessarily.

• Interrogative Sentence

1. May I borrow your jacket?
2. May I enter the classroom?
3. May I ask what your is?
4. May I have a cup of coffee?
5. How may I help you?

Might – Past Form of “May”

The past form of “May” is “Might.” It refers to the same expression as “May” do. “Might” is mostly used in sentences representing past hypothetical situations.

• Probability of a certain action (unlikely to happen)

Example: The rain might have stopped by now.

• Asking for Permission (polite manner)

Example: Might I borrow your book for 1 day?

• Giving Suggestion

Example: You might do the worksheets regularly to improve yourself.

The slight difference between “May” and “Might” is that “May” refers to the strong probability of happening of a certain event, while “Might” refers to the uncertainty of an event.

“Might” denotes a more polite manner than “May.”

Main Differences Between “Can” and “May” in Points

• The use of “Can” represents permission, possibility, offer, suggestion, and opportunity while “May” represents permission, possibility, and any wish or desire.
• “Can” is used in affirmative, negative as well as interrogative sentences while “May” is used in affirmative and interrogative sentences. There are rare cases where “May” is used in negation.
• “Can” is used in an informal nature while “May” is used in a formal nature and refers to a polite tone of expression.
• The use of “Can” shows a strong possibility while “May” shows less possibility or probability compared to “Can.”
• The negation of “Can” (Can not) is used to denote the impossibility of a certain action which means there are no chances of that action taking place. While the negation of “May” (May not) is used to denote the improbability of an action to take place. Improbability means the chances of a certain event are unlikely, but it does not mean that no chance exists. 
• “Could” is the past equivalent to “Can” while ‘Might” is the past equivalent to “May.”
• “Could” is used to show a weak possibility of an event compared to “Can” while “Might” shows less probability of an event compared to “May.”

Conclusion

“Can” and “May” are modals that represent different expressions such as permission, possibility, suggestion, offer, ability, or opportunity. They come before verbs. They do not end with “-ing” or “-ed” and are static irrespective of the subject matter of a sentence.

However, both are different from each other. “Can” is used unofficially and shows favorable chances of happening of an action. On the other hand, “May” is used in an official manner and a polite tone. Where “May” denotes permission and possibility, “Can” denotes offer, opportunity, and suggestion including permission and possibility. Both have different significance and are important in English morphology.

References

• Jiwan Books International (P) Ltd.
• https://dictionary.cambridge.org/grammar/british-grammar/may
• https://langeek.co/en/grammar/course/737/can
• https://www.ecenglish.com/learnenglish/lessons/can-modals
• https://www.masterclass.com/articles/may-vs-might-explained