Can and may difference in use. Modal verbs of assumption (must, may, might, can, etc.)

It is impossible to imagine the English language without modal verbs. Should, ought to, must, can and others like them - that integral part of the language that is taught in schools, studied in courses and worked on in every possible way. However, many, especially those who have just begun to immerse themselves in English, still have many questions - not only regarding the grammatical, but also the semantic aspect. Let's figure it out together.

We can speak English

If we talk about "can"(“to be able”), then we, as a rule, use it to denote the physical (im)ability to do something ( physical ability of doing something), designation of the potential (im)possibility of something ( possibility/impossibility), as well as requests ( requests), failures ( refusals) and offers of help ( the offer). For example:

He can swim as well as a professional sportsman(“He can swim as well as a professional athlete”) - physical ability of doing something;
She can't pass the salt to you right now(“Right now she can’t pass you the salt”) - physical disability of doing something;
Chinese can be really difficult if you haven’t learned any Eastern language before(“Chinese may seem difficult if you have not studied any Eastern language before”) - possibility;
It can’t be Ruth, she is on the islands now(“It can’t be Ruth, she’s on the islands now) - impossibility;
Can you please give me some bread?(“Can you pass me the bread?”) - request;
No, you can't do this(“No, you can’t do that”) - refusals;
Can I help you?(“How can I help?”) - offer.

It should be mentioned that when we use "can" in negatives, although we imply that someone is not allowed to do something, this is not a strict prohibition, which, for example, is implied in the meaning of “must not”. So, it would be wrong to translate "No, you can't do this" as “No, you are not allowed to do this” - the correct translation would be "No, you can't do that". Such semantic and stylistic nuances are extremely important when using modal verbs, otherwise, if you choose the wrong verb, the meaning of the entire sentence may be completely distorted.

Can in the past tense

Modal verb "can" can also be used in the past tense - like "could" And "could have". The first, in addition to standard cases of use (we can express through could all the same things that we discussed above - from describing the possibility of something to refusal; the main difference will be that we are talking about the past), we often use to do our request is more polite (especially if we are addressing a stranger or simply conducting a formal, very polite dialogue): “Could you please show me the way?”(“Could you show me the way?”). We can use the second if we want to talk about something that is possible now or was so in the past: "He could have been in your office now"(“He could be in your office right now”) or “He could have run away even yesterday”(“He could have escaped yesterday”).

We order in English

"Must", unlike “can”, it means “must”, which is why it is used in rules and orders ( obligations) - when we want to convey that doing something is strictly prohibited, or vice versa, it must be done:

You must be quiet on the lessons(“You must be quiet in class”);
You must not smoke here(“Smoking is prohibited here”) = It is strictly forbidden to smoke here.

Also, if you "can" there is a past tense form "could", then "must" there is none, this verb is most often used in the present tense. If you still need to talk about the past, then the past form is formed using “have” and the third form of the semantic verb. As a rule, "must have" implies something that should have happened, according to logic and deduction: “His bed is still warm, he must have been here”("His bed is still warm, he should have been here") or “If he had had gone to Mexico, he must have met Pablo and given it to him”("If he was in Mexico, he should have met Pablo and given it to him").

Ask permission in English

Modal verb "may" also translated as “to be able”, but, unlike “can”, it does not imply the physical ability and ability to do something, but an abstract one, and is used when we ask permission ( asking for permission), formulate a polite request ( request), we speak about the likelihood of something (possibility of something) or we do not allow someone to do something ( refusal):

May I ask, Sir?(“May I ask a question, sir?”) – asking for permission;
He may pay you a visit tomorrow(“Maybe he’ll come see you tomorrow”) – possibility of something;
May I offer you a seat?(“May I offer you a seat?”) – request;
You may not take my clothes without my permission, Sarah!(“You’re not allowed to take my things without permission, Sarah!” – refusal.

It is also important to understand that "may not" does not imply such a strong prohibition as is inherent in "must not"– if we need to make it clear that something is strictly prohibited, we need to use “must not”.

"Might", in addition to being used as the past form of "may", can be used, again, in polite requests or statements that something might happen: "Might I ask you a question, Sir?" or "It might be raining tomorrow».

If everything could already happen...

We can also use "may have" And "might have" to indicate an action that could happen now or could happen some time ago:

Three hours before midnight. She may have gone to her favorite club now(“Three hours to midnight. Maybe she left for her favorite club.”) - it is implied that she may have left now;
She may have gone to her favorite club an hour ago(“Maybe an hour ago she left for her favorite club”) - implies that she could have left some time ago.

Despite their nuances of use and stylistic shades, modal verbs are very important for the language - they will help you most accurately and expressively formulate the message that you want to convey to your interlocutor, and will also give you the opportunity to understand the semantic connotation of the phrases in which they appear.

May And might are modal verbs that have many interesting qualities. In some cases they can replace each other, in others they can act as a form of present and past tense, in others they can have completely different meanings. May And might sometimes cause difficulties for English learners, so in this article we will talk about the difference between them and examine in detail the cases of their use.

Features of the modal verbs may and might

To begin with, we propose to understand how sentences are constructed with may And might, because such proposals have several distinctive features.

In affirmative sentences after may And might we use the infinitive without a particle to. In questions may And might must be placed before the subject. In negative sentences we add to may/might particle not. To Russian may/might most often translated by the words “could”, “could”.

I might go. - I could go.

May she enter the room? - She Maybe enter the room?

I may not come. - I I can't come.

Pay attention to one feature: negation may not no shortened form.

We may not may not be at home today. - Us may not be at home today.

Negation might not may be reduced - mightn't, however, this form is rare.

It might rain today, mightn't it? - It might rain today isn't it?

Let's consider other features of modal may And might:

Might is the past tense form of the verb may, But might also used as a stand-alone modal verb.
U may And might there are general functions and there are private ones: in some cases we can only use may, in others – only might.
WITH may And might we can use the usual infinitive ( may/might do), long ( may/might be doing) and perfect ( may/might have done). Regular infinitive ( may/might do) indicates an action in the present or future, continuous - a long-term action in the present or future, perfect - an action in the past.

Also, different functions may have their own peculiarities of using infinitives. We will talk about them further.

Well, now let's figure out how may And might are used in speech.

When we use the modal verbs may and might

First, we will look at cases where both verbs can be used - may And might. Here they are:

Possibility, uncertainty– probability, uncertainty.
The most important function may/might is a probability. In this function may shows a greater degree of confidence than might. In translation into Russian we will use the words “may”, “maybe”, “should be”, “possibly”.

This function has one feature: we can use long ( may/might be doing) and perfect ( may/might have done) infinitives to describe actions in the present, past and future. Regular infinitive ( may/might do) works according to standard rules: shows the present or the future. You can observe this feature in the cases listed below, since probability and uncertainty can manifest themselves in different ways:
- We describe a typical situation or talk about a well-known fact.
  A driver may fall asleep if he doesn’t stop every two hours. - Driver can fall asleep, unless it stops every 2 hours.
  
  The flowers might have faded if I hadn't watered them regularly. - Flowers could wither, if I didn't water them regularly.
- We make a guess about what might be true. As a rule, in this case we are not very confident in our words.
  – Where is Ken? -Where is Ken?
  – No idea. He may be in the kitchen. - Don't know, May be, in the kitchen.
  
  He might not have been at the concert. – Maybe, his there wasn't at the concert.
- Nothing prevents us from performing or not performing any action. Circumstances are such that we can do something.
  We may go out tonight or we may not. – Maybe, We let's go for a walk tonight, a maybe we won't go.
  
  I might not answer the phone as I’ll be sleeping in the afternoon. - I I may not answer on the phone, since I will sleep during the day.
- We talk about our possible plans or intentions. Here may/might usually used with the continuous infinitive.
  Don't call me at midday. I might be having lunch at this time. - Don't call me at noon. I I can have lunch at this time.
  
  I may be going to Switzerland soon. – May be, I I'll leave to Switzerland soon.
And now a little life hack: if we can replace may/might in a word perhaps(possible), which means we are talking about probability.

He might not have been at the concert. = Perhaps he was not at the concert. – Maybe, he was not at the concert.

I may be going to Switzerland soon. = Perhaps I'm going to Switzerland soon. – May be, I'm leaving for Switzerland soon.
Request, asking for permission- request, request for permission.
According to the rules of classical grammar, we use may/might when we want to politely make a request to someone or ask permission to do something. However, in spoken English, native speakers increasingly use a modal verb in this function. May/might preferable can in a formal context. Also in this meaning might a more polite verb than may.

May I show you the papers, sir? – Can Shall I show you the papers, sir?

Sorry to bother you, Mr. Smith. Might I have a day-off tomorrow? - Sorry to bother you, Mr. Smith. Can I Should I take tomorrow off?
Design may/might as well.
Expression may/might as well used in such cases:
- when we have to do something because we have no other choice;
- if there is not much difference, what to do.
This expression implies the following idea: it is better to do this than to do nothing at all. There are several translation options: “there is nothing (else) left (as)”, “why not”, “it is possible and”, “it is quite possible”, “it is possible at least”. It should be noted that the combination might as well occurs more often than may as well.

We've missed our train. We might as well wait for the next one. - We missed the train. There is nothing else left but wait for the next one.

– Are you leaving now? -Are you leaving now?
– I don’t know. I might as well. - Don't know. It is possible Now.

There is nothing to do here. I may as well go somewhere else. - There's nothing to do here. Quite possible, I'll go somewhere else.
Design may/might not... but.
We use the design may/might not... but when we want to highlight some good quality in a person or thing. This construction is usually translated with the words “could not have been..., if not for...”, “would not have been, if not for...”.

These memoirs may not be a masterpiece, but the author’s life experience is invaluable. – These memoirs wouldn't be masterpiece if not the author's invaluable experience.

This girl might not have become a famous singer, but her voice was beautiful. - This girl might not be famous singer, if not her beautiful voice.

We got acquainted with the general functions of verbs may And might. Now we will look at each of them separately.

When to use the modal verb may

Some tasks are modal may didn't want to share with might. Let's figure out which ones exactly.

Permission and prohibition– permission and prohibition.
We use a modal verb may, if we allow or allow someone to do something. To disable an action, we add to may negative particle not. It should be noted that may And may not in this meaning are often found in formal speech. We also use this modal verb when we speak with an unfamiliar person, boss or subordinate. To Russian may usually translated by the word “to be able”, may not- “impossible”, “must not”, “prohibited”.

You may eat only one ice-cream at a time. - You you can eat it only one ice cream at a time.

Mr. Hicks, you may participate in the debate on Saturday. - Mr. Hicks, you you can take part in Saturday's debate.

Customers may not enter this room. – Buyers forbidden to enter to this room.

You may not play football on the grass. - You shouldn't play football on the grass.
Wishes– wishes.
By using may we can express our wishes to someone. In this case may goes to the beginning of a sentence. In Russian we will translate the modal verb with the word “let”.

May this marriage brings you a lot of joy and happiness. – Let this marriage will bring you a lot of joy and happiness.

May all your wishes come true. – Let all your wishes will come true.
Certainty- confidence.
If we believe that some action is likely to happen, if we are almost certain of it, we can add to may adverb well. This combination will be translated by the words “probably”, “quite possible”.

He may well take a taxi not to wait for a bus. - He, will probably take taxi so as not to wait for the bus.

Adam may well not want to go to the hospital with us. – Adam may well not want to come with us to the hospital.

When to use the modal verb might

U might English also has its own problems. Let's see what functions this modal verb performs.

Polite advice- polite advice.
Might as an independent modal verb, it is used to politely give advice or make an assumption about something. Most often in such cases might goes with the words: like(like, want), prefer(prefer) or want(want).

You might like to try one of our wonderful desserts. - You, maybe you want try one of our wonderful desserts.

You might prefer a cheaper accommodation. It will help you to save some money. – Maybe, You would you prefer cheaper housing. This will save you money.
Action that never happened- an action that did not happen.
Verb might shows an action that could have happened but did not. At the same time, for might followed by a perfect infinitive ( have done). Often this feature indicates that the speaker is unhappy that something was not done. This construction is translated as “could”.

He might have eaten a jar of jam if he hadn’t been full. - He could eat a jar of jam, if I weren't full.

You might have washed the dishes! – Might as well wash it dishes!
Hardly possible situation- an unlikely situation.
When we say that some situation is possible, we use and may, And might. But if we are talking about a situation that is impossible or unlikely, then we should use might. The context helps us understand whether the situation before us is real or not: something would have happened if some circumstances had not interfered. Often used to express this function. We will translate into Russian might as "could".

Alice might come here tonight, but she is working till late. – Alice could come today, but she works late.

I might finish my report if you didn’t ask me stupid questions. - I could finish report, if you didn't ask me stupid questions.

If it hadn’t been so hot yesterday, we might have gone somewhere. – If it hadn’t been so hot yesterday, we would go somewhere.
Typical situation in the past- a typical situation in the past.
Verb might can be used in situations where we want to communicate that some action was habitual, typical, or usual in the past. Usually in such cases we mention that the action took place a long time ago. Even though we are talking about action in the past, might will be used with the regular infinitive ( might do).

During the Middle Ages a girl might get married at the age of 12. – In the Middle Ages young woman could get married at the age of 12 years.

Years ago you might see just a couple of cars in the street. – Many years ago on the streets could be seen just a couple of cars.

Verb Substitute may.

When agreeing tenses and in indirect speech we will use might, even if according to the rules there should be may.

Action in the present	Action in the past
Caroline isn't talking* to Rick. They may/might have had an argument. Caroline doesn't talk* with Rick. Maybe, they quarreled.	Caroline wasn't talking* to Rick. They might have had an argument. Caroline didn't talk* with Rick. Maybe, they quarreled.
Direct speech	Indirect speech
Our coach told* us, “You may stay up a little bit later tonight.” Our trainer said* to us: “You you can go to bed a little later today."	Our coach told* us that we might stay up a little bit later tonight. Our trainer said* us that we we can go to bed a little later today.

Typically, English learners have the most difficulty with the notorious perfect infinitive. Let's watch a video in which they will tell us about the cases of using the perfect infinitive and other subtleties may And might.

And to finally consolidate the topic and understand how well you understand it, take our test.

Test

Modal verbs may and might in English

For expression possibilities or capabilities perform an action (with Indefinite Infinitive*).
I can do it now. → I can do it now.
When possibility not allowed that the action actually took place (with Perfect Infinitive**).
He cannot have done it. → It can't be that he did this.

COULD is used:

For expression possibilities or capabilities perform an action in the past (with Indefinite Infinitive).
He could swim very well when he was young. → He could swim well when he was young.
IN indirect speeches depending on the verb in past time (with Indefinite Infinitive and Perfect Infinitive).
I said that he could speak English. → I said that he can speak English.
I said that he couldn't have done that. → I said he couldn't do it.
IN

If he tried, he could do

If he had tried, he could have done it. → If he tried, he could do it.

MAY is used:

For expression permissions(with Indefinite Infinitive).
You may go home now. → You can now go home.
For expression assumptions:
a) relating to the present or future (with Indefinite Infinitive).
It may rain today. → It might rain today.
b) relating to the past (with Perfect Infinitive)
He may have returned to London. → He may have returned to London.

MIGHT is used:

IN indirect speeches depending on the verb in past time:
a) to express permission (with Indefinite Infinitive).
She said that he might take her doc. → She said that he could take her dictionary.
b) to express an assumption (with Indefinite Infinitive and Perfect Infinitive).
He said that she might know their address. → He said that she might know their address.
He said that she might have lost their address. → He said that she might have lost their address.
IN main part of conditional sentences:
a) in conditional sentences of the second type (with Indefinite Infinitive).
If you tried, you might get the boo k. → If you tried, you could get this book.
b) in conditional sentences of the third type (with Perfect Infinitive).
If he had been here, he might have helped us. → If he were here, he could help us.

Difference in the use of CAN (COULD) and MAY (MIGHT)

If the verb Can used with the meaning capable, capable, capable, then CAN (COULD) is used. If the verb Can used with the meaning allowed, then MAY (MIGHT) is used. Compare:
Can I come in? - Yes, you can.- Meaning physical ability enter, i.e. yes, you are physically capable of doing it.
May I come in? - Yes, you may.- Meaning permission enter, i.e. yes, you are allowed, allowed to do it. *Indefinite Infinitive - indefinite infinitive, simple form of the infinitive. Formed without help and an auxiliary verb.
**Perfect Infinitive - perfect infinitive, complex form of the infinitive. Formed using the verb to have + Past Participle (past participle).

This may arise because they are both often translated into Russian as “to be able”, for example:

– May I ask you something? – Can I ask you something?

– Can you wait for a while? -Can you wait a little?

In this article we will look at when to say can and when may and what is the difference between them.

Can or May? Main Difference

Very briefly, the main difference is that can usually implies the physical ability to do something, and may- permission, permission. In other words, “I can” is similar to “I can,” and “I may” is similar to “I can.”

I can lift a car. - I Can lift the car (I can physically).

I may eat all the cookies. - To me Can eat all the cookies (I was allowed).

But there are other nuances, let’s consider them in more detail.

When do we say Can?

First let's look at the cases when we say can.

The physical ability to do something.

I can breath underwater. – I can breathe underwater.

Thomas can sleep four hours a day and feel well. Thomas can sleep four hours a day and feel fine.

I can't help you. – I can’t help you (I don’t have the opportunity).

The ability to do something.

This means not just physical ability, but the presence of skills.

Can do you ride a horse? – Do you know how to ride a horse?

I can't play basketball – I don’t know how to play basketball.

A question about physical ability or skill.

When you ask a question, you are not asking whether, for example, an airplane is allowed to fly in space, but whether it is physically capable of doing so.

Can an airplane fly in the space? – Can a plane fly in space?

Can do you play the piano? – Do you know how to play the piano?

Expression of surprise, doubt, disbelief

Can will it be the truth? -Can this be true?

No way, you can't have done it! - It can’t be, you couldn’t do that!

When do we say May?

Assumption about some probability, possible action.

In this case, along with may often used might with a slight difference in meaning (if might, then the possibility seems slightly less likely).

Take an umbrella, It may/might rain tonight. - Take an umbrella, it might rain in the evening.

The table is reserved but there might be another option. – This table has been booked, but perhaps there is another option.

Permission and prohibition (old school English).

In strictly correct “old school” English, permission and prohibition are expressed using may

May I suggest another decision? – Can I suggest another solution?

You may not play in the garden. - You can't play in the garden.

However, in modern English in these cases they also use can, And may.

When can you say both Can and May?

Asking or giving permission

Dad, can/may I take your car? - Dad, can I take your car?

Oh, you finished painting the fence! Well done! You can/may go now. - Oh, you've already painted the fence! Well done! You can go.

As I mentioned above, it used to be considered the norm to use may to ask or give permission. Strictly speaking, the question with can implies physical possibility, and the question with may- permission. There is a famous joke: a student raises his hand and asks “Can I go to the bathroom?” (can I go to the toilet?), and the teacher answers “I don’t know, can you?” (I don't know, can you?)

However, in modern English almost no one adheres to these differences; on the contrary, sentences with can in the “permissive” sense are even more common (this is discussed in this article on Merriam-Webster). I once came across an interesting discussion on the Duolingo app, where it was mentioned that the “May I” generation had finally lost ground to the “Can I” generation:

“I think the last time I saw “May I” was in the 1962 movie Music Man, where a piano teacher was trying to get his student to say it. I am afraid that the “May I” generation has lost to the “Can I” generation. (screenshot from the Duolingo app)

Ban

In English, a prohibition can be expressed in different ways, the strictest way is. If we say, “You must not cross this line,” it is something like “You are prohibited from crossing this line,” that is, we are talking about a strict, categorical prohibition. Expressions of prohibition with cannot And may softer, but there is a small, not always significant difference in meaning between them.

Prohibition with can’t means some abstract neutral “forbidden”.

I'm sorry but you can't park here. - Sorry, but you can't park here.

You can't smoke in the park. – You can’t smoke in the park.

Ban from may not may be perceived as a more personal prohibition with a hint of edification and instruction. Something like “you are forbidden”, “you are not allowed”, “you are not allowed”.

You may not play with Bobby, he is a bully! “You can’t play with Bobby, he’s a bully!”

You may not go the party, you are grounded. – You can’t (I don’t allow) you to go to the party, you’re punished

Note: to ground – punish a child with “house arrest”.

Friends! I don't currently tutor, but if you need a teacher, I recommend this wonderful site- there are native (and non-native) language teachers there 👅 for all occasions and for any pocket 🙂 I myself took more than 50 lessons with the teachers I found there!

Modal verbs are auxiliary verbs that do not express an action, but describe the speaker’s attitude to the action expressed by the main (semantic) verb. They are used with the infinitive of the semantic verb following them, and show the likelihood, necessity or desirability of performing the action expressed by the infinitive.

Modal verbs include: (can, could, must, should, ought to, may, might, will, would, shall, be to, have to, need and dare).

Modal verbs	Meaning	Examples
	physical or mental ability/ability	I can swim very well. – I can swim very well.
	opportunity	You can go now. - You can go now. You cannot play football in the street. – You can’t play football on the street.
	probability	They can arrive any time. - They can come at any time.
	astonishment	Can he have said that? - Did he really say that?
	doubt, distrust	She can't be waiting for us now. “It can’t be that she’s waiting for us now.”
	permission	Can we go home? -Can we go home?
	polite request	Could you tell me what time it is now? - Could you tell me what time it is now?
	permission	May I borrow your book? – Can I borrow a book from you?
	assumption	She may not come. - She may not come.
	opportunity	In the museum you may see many interesting things. – In the museum you can see a lot of interesting things.
	reproach - only MIGHT (+ perfect infinitive)	You might have told me that. “You could have told me that.”
	obligation, necessity	He must work. He must earn money. - He must work. He must earn money.
	probability (strong degree)	He must be sick. - He must be sick.
	ban	Tourists must not feed animals in the zoo. — Tourists should not feed animals in the zoo.
SHOULD/OUGHT TO	moral obligation	You ought to be polite. – You must be kind.
	advice	You should see a doctor. – You should go to the doctor.
	reproach, ban	You should have taken the umbrella. -You should have taken an umbrella with you.

TO BE TO	command, order	You are to go straight to your room now. “You should go to your room now.”
TO BE TO	plan	I was to be there at 5 sharp. “I was supposed to be there at five sharp.”
TO HAVE TO	necessity (forced, has to)	As I was to be there at 5 sharp, I had to take a taxi. - Since I had to be there exactly at five, I had to take a taxi.
	decree, duty	These rules shall apply in all circumstances. – These rules will apply under any circumstances.
	threat	You shall suffer. - You will suffer.
	request for guidance	Shall I open the window? - Should I open the window?
	willingness, unwillingness/refusal	The door won't open. — The door doesn't open.
	polite request	Will you go with me? -Can you come with me?
	willingness, unwillingness/refusal	He would not answer this question. - He will not answer this question.
	polite request	Would you please come with me? - Could you come with me?
	repetitive/habitual action	We would talk for hours. – We talked for hours.
	necessity	Do you need to work so hard? – Do you have to work so much?
NEEDN'T	no need	She needn't go there. - She doesn't need to go there.
	Dare	How dare you say that? - How dare you say such a thing?