may/might/can

"May" is used to indicate permission or possibility. "Might" is the past tense of "may" and indicates possible intention. For some speakers, "may" indicates a higher probability than "might." "I may go to the movie tonight" (quite likely); "I might go to the movie tonight (less likely)."

Webster"s says "might" is "used in auxiliary function to express permission, liberty, probability, possibility in the past or a present condition contrary to fact or less probability or possibility than may or as a polite alternative to may or to ought or should .

Webster"s defines "may" as "have permission to. . . have liberty to <"you may say what you please, I won"t do it"> . . .used nearly interchangeably with "can""; it defines "might" as "used in auxiliary function to express permission, liberty, probability, possibility in the past . . . or a recent condition contrary to fact<"if he were older he might understand"> or less probability or possibility than "may" <"might get there before it rains"> <"might be a good idea to wait and see"> or as a polite alternative to "may" <"might I ask who is calling"> or to "ought" or "should" <"you might at least apologize">."

"May" usually implies permission or to have freedom, which may or may not be granted externally; i.e., you can give yourself permission or freedom to do something, such as go to the store. "May" is also sometimes used interchangeably with "can" and "might," and is also used to express a wish, desire, purpose or expectation. Remember, it is a present tense auxiliary verb. Also from Webster"s, ""Can" and "may" are most frequently interchangeable in senses denoting possibility; because the possibility of one"s doing something may depend on another"s acquiescence, they have also become interchangeable in the sense denoting permission."

Evans and Evans say:" "He may" does not have the "s" ending we ordinarily expect in a present tense verb. This is because "may" is an ancient past tense form. But it had come to be felt as a present tense by the time English became a written language. "Might" is a new past tense form that was created for it, but which has also come to be felt as a present tense. Today "may" and "might" are treated as subjunctive tenses. They represent different degrees of probability rather than a difference in time. The present subjunctive form "may" represents an event as possible while the past subjunctive form "might" represents it as possible but not likely, as in "he may come" and "he might come". In asking permission, "might" is more diffident than "may", as in "might I come in?", since it politely suggests that the speaker does not expect to get what he is asking for and so won"t be surprised by a refusal. . . ." Evans and Evans also imply a polite, almost deferential, way of putt! ing it. "May" and "might" are used similarly to "can" and "could." If you are at a job interview, you might say either, "I can start next Monday" or "I could start next Monday"; the first one is more direct, more self-confident, but depending on the interviewer"s personality, "can" might be seen as presumptuous, so the softer, more indirect "could" might be a better choice. Similarly, compare the difference in tone of these two statements that might be made by your date at the end of your first evening out together: "I want to see you again" and "I would like to see you again." The first is more aggressive; the second is softer and more along the lines of a request.

They go on to say, "In refusing permission, "you may not" is felt to be disagreeably personal and dictatorial and "you cannot" is almost universally preferred. In discussing a decision, or arguing about it, "can" is required. We never say "why mayn"t I?" or "mayn"t I?" but always "why can"t I?" or "can"t I?" since we are assuming that something more than a whim is involved. In granting permission "may" is still used occasionally, as in "you may keep it till Friday". But most people now feel that it is more courteous, less autocratic, to say "you can keep it till Friday". In asking permission, "may" is generally felt to be more polite than "can", as in "may I look at it?" but "can" is also used here, as in "can I look at it?" Since the speaker knows very well that he is able to look at it, this use of "can" is simply carrying politeness one step further by refusing to question the other person"s good will. In time, this too may be accepted as the more polite form, but that! is not yet the case."

"May" is used not just for permission, but also for possibility, as "might" is, and as "can" is. It has long been used that way, and there is no reason not to continue to use it that way, as long as your meaning is clear. "Your broken arm may take two months to heal" means not that I"m giving your arm permission to heal within two months, but that it"s possible that it will take that long to heal. If I say "Your broken arm may take two months to heal. It might even take four months," I am saying that it"s possible that your arm will take two months to heal--and it"s also possible, although not likely, that it will take as long as four months. They both indicate possibility, but in different degrees. I can also say "A broken arm can take as long as four months to heal. Yours, however, may not take that long. In fact, you might be out of the cast in as little as two months." All three of these are statements of possibility. The first is "can" in the sense of physical possib! ility; the second is "may" in the sense of "there is a chance that"; the third is "might" in the sense of "there is a chance that, but it isn"t likely."

If it"s ambiguous in context whether permission or possibility is meant, a rewrite is in order. But there is no reason that I can see to take away the possibility sense of "may" simply because "may" is also used in giving permission. After all, "can" is increasingly encroaching upon "may" in that sense. If it continues to do so (as looks likely), and if others decide to adopt the distinction between "may" and "might" for simplicity"s sake, "may" may well drop out of the language altogether sometime in the future.

Swan"s Practical English Usage says, "The commonest uses of "may" and "might" are to talk about possibility, and to ask for (and give) permission. . . . "Might" is not the past of "may"; it suggests a smaller (present or future) probability than "may"." And Evans and Evans say, ""May" represents an event as possible while. . ."might" represents it as possible but not likely."

R. L. Trask, in Mind the Gaffe: The Penguin Guide to Common Errors in English (2001), says, . . ."might have" is counterfactual: it is always followed by something that is not true. But "may have" is not counterfactual: it is followed by something which is not known to be false. This contrast is of central importance in standard English, and mastery of it is essential. So, ignore all those football coaches who routinely intone *If it hadn"t been for that dodgy call, we may have won". Standard English absolutely requires "might have won" here, and, if you find this unnatural, you will simply have to grit your teeth and learn it. You can"t imagine how awful that non-standard "may have" sounds to careful writers." Rodney Huddleston in the Cambridge Grammar of the English Language (2002) considers this a dialectical variation. In Dialect A the usage is ungrammatical; in Dialect B it is grammatical. He concludes (p. 203): "Conservative usage manuals tend to disapprove of the Dialect B usage, but it is becoming increasingly common, and should probably be recognised as a ! variant within Standard English.

Merriam Webster"s Dictionary of English Usage says, "On a more puzzling note, a few commentators. . .do note the puzzling use of "may" where "might" would be expected. There seem to be two places where such substitution occurs: in describing hypothetical conditions, and in a context normally calling for the past tense. . . : If he"d have released the ball a second earlier--when [the pass receiver] made his cut--he may have had a touchdown. --Dan Dierdorf, CBS television, 20 Dec. 1986 "Here "might have had a touchdown" would have been expected. "In the second example we have a context where the past is called for: Born in Buffalo, N.Y., he may have gone to Princeton. . .but he made his reputation as a railroader. --Forbes", 15 Sept. 1970 "This one is especially confusing since "may" in such surroundings suggests that the writer does not know whether he went to Princeton; "might" (which is the verb we would have expected) would suggest that he could have gone if he had want! ed to. "No one has a satisfying explanation for why these substitutions occur, and we are as stumped as everyone else. Here is about all we can tell you: we have more British evidence for the substitution (and more notice is taken of it by British commentators) than we have American evidence. But we do have both. The substitution is more frequent in speech than in writing. British evidence and British comment suggest that in print it is most likely to be found in the newspapers. . . ."

Besides being the past tense of can, "could" is also called a modal. That means that it sets up a condition that may or may not be real. Consider these differences. I could go if he would ask me. = This is a condition, based on another premise. I cancelled my plans before I realized I could go. = This is a simple past tense. "Can" and "may" are most frequently interchangeable in senses denoting possibility. The original definition of "can" was "to know of, to know how," and carried with it the notion of knowing how to do something--mental ability rather than physical ability, although this was later extended to physical ability. From these two uses, "can" came to take on the connotation of possibility. The transition from "possibility" to "permission" ("may") is subtler than the handbooks think. It comes from permission given by not inhibiting or prohibiting; thus, possibility.

How may/can I help you? You are being polite when you say "may," but you are being practical when you say "can," which expresses an ability.

grammarNOW! says:

In present-day English, there is little if any difference between the uses of these words when they refer to either possibility or permission. But at least retaining the difference in degree between "may" and "might" enables us to use more precision when we speak of possibility. On the other hand, if no one understands the distinction anymore, why bother? I think keeping—and teaching--such distinctions adds breadth to the language.

"May" is used to indicate permission or possibility. "Might" is the past tense of "may" and indicates possible intention. For some speakers, "may" indicates a higher probability than "might." "I may go to the movie tonight" (quite likely); "I might go to the movie tonight (less likely)."

Webster"s says "might" is "used in auxiliary function to express permission, liberty, probability, possibility in the past or a present condition contrary to fact or less probability or possibility than may or as a polite alternative to may or to ought or should .

Webster"s defines "may" as "have permission to. . . have liberty to <"you may say what you please, I won"t do it"> . . .used nearly interchangeably with "can""; it defines "might" as "used in auxiliary function to express permission, liberty, probability, possibility in the past . . . or a recent condition contrary to fact<"if he were older he might understand"> or less probability or possibility than "may" <"might get there before it rains"> <"might be a good idea to wait and see"> or as a polite alternative to "may" <"might I ask who is calling"> or to "ought" or "should" <"you might at least apologize">."

"May" usually implies permission or to have freedom, which may or may not be granted externally; i.e., you can give yourself permission or freedom to do something, such as go to the store. "May" is also sometimes used interchangeably with "can" and "might," and is also used to express a wish, desire, purpose or expectation. Remember, it is a present tense auxiliary verb. Also from Webster"s, ""Can" and "may" are most frequently interchangeable in senses denoting possibility; because the possibility of one"s doing something may depend on another"s acquiescence, they have also become interchangeable in the sense denoting permission."

Evans and Evans say:" "He may" does not have the "s" ending we ordinarily expect in a present tense verb. This is because "may" is an ancient past tense form. But it had come to be felt as a present tense by the time English became a written language. "Might" is a new past tense form that was created for it, but which has also come to be felt as a present tense. Today "may" and "might" are treated as subjunctive tenses. They represent different degrees of probability rather than a difference in time. The present subjunctive form "may" represents an event as possible while the past subjunctive form "might" represents it as possible but not likely, as in "he may come" and "he might come". In asking permission, "might" is more diffident than "may", as in "might I come in?", since it politely suggests that the speaker does not expect to get what he is asking for and so won"t be surprised by a refusal. . . ." Evans and Evans also imply a polite, almost deferential, way of putt! ing it. "May" and "might" are used similarly to "can" and "could." If you are at a job interview, you might say either, "I can start next Monday" or "I could start next Monday"; the first one is more direct, more self-confident, but depending on the interviewer"s personality, "can" might be seen as presumptuous, so the softer, more indirect "could" might be a better choice. Similarly, compare the difference in tone of these two statements that might be made by your date at the end of your first evening out together: "I want to see you again" and "I would like to see you again." The first is more aggressive; the second is softer and more along the lines of a request.

They go on to say, "In refusing permission, "you may not" is felt to be disagreeably personal and dictatorial and "you cannot" is almost universally preferred. In discussing a decision, or arguing about it, "can" is required. We never say "why mayn"t I?" or "mayn"t I?" but always "why can"t I?" or "can"t I?" since we are assuming that something more than a whim is involved. In granting permission "may" is still used occasionally, as in "you may keep it till Friday". But most people now feel that it is more courteous, less autocratic, to say "you can keep it till Friday". In asking permission, "may" is generally felt to be more polite than "can", as in "may I look at it?" but "can" is also used here, as in "can I look at it?" Since the speaker knows very well that he is able to look at it, this use of "can" is simply carrying politeness one step further by refusing to question the other person"s good will. In time, this too may be accepted as the more polite form, but that! is not yet the case."

"May" is used not just for permission, but also for possibility, as "might" is, and as "can" is. It has long been used that way, and there is no reason not to continue to use it that way, as long as your meaning is clear. "Your broken arm may take two months to heal" means not that I"m giving your arm permission to heal within two months, but that it"s possible that it will take that long to heal. If I say "Your broken arm may take two months to heal. It might even take four months," I am saying that it"s possible that your arm will take two months to heal--and it"s also possible, although not likely, that it will take as long as four months. They both indicate possibility, but in different degrees. I can also say "A broken arm can take as long as four months to heal. Yours, however, may not take that long. In fact, you might be out of the cast in as little as two months." All three of these are statements of possibility. The first is "can" in the sense of physical possib! ility; the second is "may" in the sense of "there is a chance that"; the third is "might" in the sense of "there is a chance that, but it isn"t likely."

If it"s ambiguous in context whether permission or possibility is meant, a rewrite is in order. But there is no reason that I can see to take away the possibility sense of "may" simply because "may" is also used in giving permission. After all, "can" is increasingly encroaching upon "may" in that sense. If it continues to do so (as looks likely), and if others decide to adopt the distinction between "may" and "might" for simplicity"s sake, "may" may well drop out of the language altogether sometime in the future.

Swan"s Practical English Usage says, "The commonest uses of "may" and "might" are to talk about possibility, and to ask for (and give) permission. . . . "Might" is not the past of "may"; it suggests a smaller (present or future) probability than "may"." And Evans and Evans say, ""May" represents an event as possible while. . ."might" represents it as possible but not likely."

R. L. Trask, in Mind the Gaffe: The Penguin Guide to Common Errors in English (2001), says, . . ."might have" is counterfactual: it is always followed by something that is not true. But "may have" is not counterfactual: it is followed by something which is not known to be false. This contrast is of central importance in standard English, and mastery of it is essential. So, ignore all those football coaches who routinely intone *If it hadn"t been for that dodgy call, we may have won". Standard English absolutely requires "might have won" here, and, if you find this unnatural, you will simply have to grit your teeth and learn it. You can"t imagine how awful that non-standard "may have" sounds to careful writers." Rodney Huddleston in the Cambridge Grammar of the English Language (2002) considers this a dialectical variation. In Dialect A the usage is ungrammatical; in Dialect B it is grammatical. He concludes (p. 203): "Conservative usage manuals tend to disapprove of the Dialect B usage, but it is becoming increasingly common, and should probably be recognised as a ! variant within Standard English.

Merriam Webster"s Dictionary of English Usage says, "On a more puzzling note, a few commentators. . .do note the puzzling use of "may" where "might" would be expected. There seem to be two places where such substitution occurs: in describing hypothetical conditions, and in a context normally calling for the past tense. . . : If he"d have released the ball a second earlier--when [the pass receiver] made his cut--he may have had a touchdown. --Dan Dierdorf, CBS television, 20 Dec. 1986 "Here "might have had a touchdown" would have been expected. "In the second example we have a context where the past is called for: Born in Buffalo, N.Y., he may have gone to Princeton. . .but he made his reputation as a railroader. --Forbes", 15 Sept. 1970 "This one is especially confusing since "may" in such surroundings suggests that the writer does not know whether he went to Princeton; "might" (which is the verb we would have expected) would suggest that he could have gone if he had want! ed to. "No one has a satisfying explanation for why these substitutions occur, and we are as stumped as everyone else. Here is about all we can tell you: we have more British evidence for the substitution (and more notice is taken of it by British commentators) than we have American evidence. But we do have both. The substitution is more frequent in speech than in writing. British evidence and British comment suggest that in print it is most likely to be found in the newspapers. . . ."

Besides being the past tense of can, "could" is also called a modal. That means that it sets up a condition that may or may not be real. Consider these differences. I could go if he would ask me. = This is a condition, based on another premise. I cancelled my plans before I realized I could go. = This is a simple past tense. "Can" and "may" are most frequently interchangeable in senses denoting possibility. The original definition of "can" was "to know of, to know how," and carried with it the notion of knowing how to do something--mental ability rather than physical ability, although this was later extended to physical ability. From these two uses, "can" came to take on the connotation of possibility. The transition from "possibility" to "permission" ("may") is subtler than the handbooks think. It comes from permission given by not inhibiting or prohibiting; thus, possibility.

How may/can I help you? You are being polite when you say "may," but you are being practical when you say "can," which expresses an ability.

grammarNOW! says:

In present-day English, there is little if any difference between the uses of these words when they refer to either possibility or permission. But at least retaining the difference in degree between "may" and "might" enables us to use more precision when we speak of possibility. On the other hand, if no one understands the distinction anymore, why bother? I think keeping—and teaching--such distinctions adds breadth to the language.