May vs Might: Understanding the Difference

"May" and "might" are both modal verbs that express possibility and permission, but they differ in degree of certainty and formality. Understanding when to use each is essential for precise English communication. This comprehensive guide will help you master this important distinction.

Quick Answer

• May = permission (more formal) / possibility with higher likelihood (present/future)
• Might = possibility with lower likelihood / past form of "may" / more tentative/polite

Key Insight: Both express possibility, but may suggests something is more likely to happen, while might suggests it's less likely or more uncertain.

Understanding Modal Verbs

Before diving into "may" and "might," it's important to understand that they're modal verbs (also called modal auxiliaries).

Characteristics of Modal Verbs:

1. No "s" in third person: "He may" (not "he mays")
2. Followed by base verb: "may go" (not "may to go" or "may going")
3. No infinitive form: Can't say "to may" or "to might"
4. No past participle: Can't say "have mayed" or "have mighted"
5. Same form for all subjects: I/you/he/she/it/we/they may

Understanding "May" - Permission and Possibility

May is a modal verb with two primary uses: permission and possibility.

Use 1: Permission (Formal)

May is used to ask for or give permission formally.

Asking Permission:

• "May I leave early today?" (formal request)
• "May I ask you a question?" (polite request)
• "May we begin?" (formal request)
• "May I borrow your pen?" (polite request)
• "May I use your phone?" (formal request)

Giving Permission:

• "Yes, you may leave." (granting permission)
• "You may enter now." (granting permission)
• "Students may use calculators." (permission granted)
• "You may speak freely." (permission granted)
• "Visitors may park here." (permission granted)

Denying Permission:

• "No, you may not leave." (denying permission)
• "You may not smoke here." (prohibition)
• "Students may not use phones in class." (prohibition)

Use 2: Possibility (Higher Likelihood)

May expresses possibility in the present or future, suggesting something is fairly likely.

Present Possibility:

• "It may be true." (it's possibly true, fairly likely)
• "She may be at home now." (she's possibly home, decent chance)
• "He may know the answer." (he possibly knows, reasonable likelihood)
• "This may be the solution." (possibly the solution, good chance)
• "They may be right." (they're possibly right, fair likelihood)

Future Possibility:

• "It may rain tomorrow." (there's a good possibility)
• "I may go to the party." (I'm considering it, decent likelihood)
• "She may call later." (she might, fairly likely)
• "We may need more time." (we possibly need it, likely)
• "This may help you." (it possibly will help, good chance)

Present Perfect Possibility (May Have):

• "She may have left already." (possibly left, fairly likely)
• "He may have forgotten." (possibly forgot, reasonable chance)
• "They may have missed the train." (possibly missed it)
• "I may have been wrong." (possibly wrong)

Understanding "Might" - Lower Possibility and Past

Might is also a modal verb expressing possibility, but with lower likelihood or more uncertainty.

Use 1: Possibility (Lower Likelihood)

Might expresses possibility with less certainty than "may."

Less Likely Possibility:

• "It might be true." (possibly true, but less certain than "may")
• "She might be at home." (possibly home, but doubtful)
• "He might know the answer." (possibly knows, but uncertain)
• "This might work." (possibly works, but not confident)
• "They might be right." (possibly right, but probably not)

Tentative Future Possibility:

• "It might rain tomorrow." (slight possibility, less likely)
• "I might go to the party." (considering, but probably won't)
• "She might call later." (possibly, but doubtful)
• "We might need help." (possibly need it, uncertain)
• "This might be difficult." (possibly difficult, somewhat likely)

Present Perfect Possibility (Might Have):

• "She might have left." (possibly left, but uncertain)
• "He might have forgotten." (possibly forgot, less certain)
• "They might have seen us." (possibly saw us, doubtful)
• "I might have made a mistake." (possibly made one)

Use 2: Past Form in Conditional Sentences

Might is used in certain conditional and past contexts where "may" cannot be used.

Conditional Sentences:

• "If I studied harder, I might pass." (hypothetical)
• "If she called, I might answer." (hypothetical)
• "If we left now, we might make it." (hypothetical)
• "If I were you, I might reconsider." (hypothetical)

Past Reported Speech:

• She said she might come. (reporting past statement)
• He thought he might be late. (past thought)
• They wondered if it might rain. (past wondering)

Use 3: Polite Suggestions and Requests

Might can be more tentative and polite than "may" for suggestions.

Polite Suggestions:

• "You might want to check that." (gentle suggestion)
• "You might consider waiting." (soft suggestion)
• "We might try another approach." (tentative suggestion)
• "It might be best to wait." (careful suggestion)
• "You might like this book." (gentle recommendation)

Tentative Requests:

• "Might I suggest an alternative?" (very polite, formal)
• "Might we discuss this later?" (very polite, formal)
• (Note: "might" for permission is very formal and old-fashioned)

The Likelihood Scale

Understanding the difference in certainty:

Certainty/Likelihood Scale:

Certainty Level	Expression	Example
Certain	will	"It will rain." (100% certain)
Very Likely	should, ought to	"It should rain." (very probable)
Fairly Likely	may	"It may rain." (good possibility)
Less Likely	might	"It might rain." (slight possibility)
Possible	could	"It could rain." (possible but uncertain)
Unlikely	might not	"It might not rain." (probably won't)

Comparative Examples:

Higher Likelihood (May):

• "She may be at home." (50-70% chance)
• "It may rain tomorrow." (fairly possible)
• "This may work." (decent chance)
• "He may come to the party." (reasonable likelihood)

Lower Likelihood (Might):

• "She might be at home." (30-50% chance)
• "It might rain tomorrow." (less possible)
• "This might work." (less confident)
• "He might come to the party." (less likely)

Key Differences

May	Might
Higher likelihood	Lower likelihood
More confident	More tentative
Permission (formal)	Rarely used for permission
Present/future possibility	Past form of "may"
"It may happen" (fairly likely)	"It might happen" (less likely)
"May I leave?" (permission)	"Might I leave?" (very old-fashioned)
Stronger possibility	Weaker possibility
More certain	More uncertain

Comprehensive Comparison Chart

Aspect	May	Might
Certainty	Higher (50-70%)	Lower (30-50%)
Permission	Yes (formal)	Very rare (archaic)
Possibility	More likely	Less likely
Formality	Formal for permission	More tentative
Tone	Confident	Uncertain
Example	"I may go" (likely)	"I might go" (less likely)
Conditional	Limited use	Common use
Past context	Cannot be used alone	Can be used

Memory Tricks

1. The Certainty Scale

• MAY = More likely, Almost certain, Yes probably
• MIGHT = Maybe, Iffy, Guess, Hopefully, Tentative

2. The Alphabet Rule

• MAY comes before MIGHT in alphabet
• MAY = More likely (comes first)
• MIGHT = Less likely (comes second)

3. The Permission Test

• If asking permission formally → use MAY
• "May I...?" (correct for permission)
• "Might I...?" (sounds old-fashioned)

4. The Confidence Test

• If you're fairly confident → MAY
• If you're doubtful or tentative → MIGHT

5. The "A" vs "I" Trick

• MAY has an A → Almost certain, Affirmative
• MIGHT has an I → Iffy, In doubt

6. The Present/Past Connection

• MAY is the present form
• MIGHT is the past form (in some contexts)
• "He said he might come" (past reported speech)

7. The Replacement Test

• If you can replace with "will probably" → MAY
• If you can replace with "could possibly" → MIGHT

Common Mistakes and Corrections

Incorrect Usage:

1. "Might I use the bathroom?" (Too formal/archaic in modern English)
2. "It might definitely rain." (Contradiction - might = uncertain, definitely = certain)
3. "You may fail if you don't study." (Conditional should use might)
4. "He may have been there yesterday." (When you're very uncertain, might is better)
5. "May I come if I studied?" (Conditional should use might)
6. "Students might not use phones in class." (Should be "may not" for prohibition)
7. "She said she may come tomorrow." (Reporting past speech should use might)
8. "If I were rich, I may travel the world." (Conditional should use might)

Correct Usage:

1. "May I use the bathroom?" (modern, appropriate)
2. "It might rain." or "It will definitely rain."
3. "You might fail if you don't study."
4. "He might have been there yesterday." (very uncertain)
5. "I might come if I studied." (conditional)
6. "Students may not use phones in class." (prohibition)
7. "She said she might come tomorrow." (reported speech)
8. "If I were rich, I might travel the world." (conditional)

Detailed Usage Examples

"May" for Permission:

Asking Permission (Formal):

• "May I ask you a personal question?" (polite, formal)
• "May we schedule a meeting?" (formal request)
• "May I leave work early today?" (formal request to boss)
• "May I have your attention, please?" (polite request)
• "May I sit here?" (polite request)
• "May I speak with the manager?" (formal request)

Granting Permission:

• "Yes, you may proceed." (formal permission)
• "You may begin the exam." (authorization)
• "Students may leave when finished." (permission granted)
• "You may take a break." (permission granted)
• "Guests may use the pool." (permission granted)

Formal Rules and Regulations:

• "Passengers may carry one bag." (what's allowed)
• "Employees may work from home." (what's permitted)
• "Customers may return items within 30 days." (policy)
• "You may not smoke on the premises." (prohibition)
• "Photography may not be allowed." (restriction)

"May" for Possibility (Higher Likelihood):

Present Situations:

• "She may be right about that." (fairly likely)
• "This may be the best option." (good possibility)
• "He may already know." (decent chance)
• "The answer may surprise you." (fairly likely)
• "It may be too late." (reasonable possibility)

Future Events:

• "I may visit next month." (good possibility, considering it)
• "The project may finish early." (fairly possible)
• "They may announce results tomorrow." (likely)
• "We may need to reschedule." (good chance)
• "She may join us for dinner." (fairly likely)

Present Perfect (May Have):

• "She may have already left." (fairly likely she left)
• "He may have called while I was out." (decent possibility)
• "They may have forgotten." (reasonable chance)
• "I may have seen him before." (fairly possible)
• "The package may have arrived." (good chance)

Formal Statements and Reports:

• "This may cause side effects." (warning, fairly possible)
• "Results may vary." (fairly likely variation)
• "Delays may occur." (good possibility)
• "Prices may change without notice." (fairly possible)

"Might" for Possibility (Lower Likelihood):

Uncertain Present:

• "She might be right, but I doubt it." (less likely)
• "This might work, but I'm not sure." (uncertain)
• "He might know, but probably not." (doubtful)
• "It might be true." (somewhat uncertain)
• "They might be home." (not very likely)

Tentative Future:

• "I might visit, but probably won't." (less likely)
• "It might snow tonight." (slight possibility)
• "She might change her mind." (somewhat possible)
• "We might go to the movies." (considering, uncertain)
• "They might be late." (somewhat possible)

Present Perfect (Might Have):

• "She might have left." (possibly, but uncertain)
• "He might have forgotten." (less certain possibility)
• "They might have taken a different route." (possible but doubtful)
• "I might have been mistaken." (somewhat possible)
• "The email might have gone to spam." (possible explanation)

"Might" in Conditional Sentences:

Hypothetical Present/Future:

• "If I had time, I might help you." (hypothetical)
• "If it were cheaper, we might buy it." (hypothetical)
• "If she asked nicely, he might agree." (hypothetical)
• "If we hurried, we might catch the train." (hypothetical)
• "If I won the lottery, I might quit my job." (hypothetical)

Past Conditional (Might Have):

• "If I had known, I might have come." (past hypothetical)
• "If she had studied, she might have passed." (past hypothetical)
• "If we had left earlier, we might have made it." (past hypothetical)
• "If he had asked, I might have said yes." (past hypothetical)

"Might" for Polite Suggestions:

Gentle Recommendations:

• "You might want to reconsider." (soft suggestion)
• "We might try a different approach." (tentative suggestion)
• "You might like this restaurant." (gentle recommendation)
• "It might be wise to wait." (careful suggestion)
• "You might find this interesting." (soft suggestion)

Tactful Advice:

• "You might be pushing yourself too hard." (gentle observation)
• "We might be overlooking something." (tactful suggestion)
• "You might want to check with a doctor." (careful advice)
• "It might be time for a change." (tactful suggestion)

"Might" in Reported Speech:

Past Thoughts and Statements:

• She said she might attend. (reporting past statement)
• He thought he might be late. (past thought)
• They warned it might be dangerous. (past warning)
• I wondered if she might call. (past wondering)
• He mentioned he might need help. (past mention)

Special Cases and Advanced Usage

May vs Might in Questions:

Direct Questions:

• "May I help you?" ✓ (common, polite)
• "Might I help you?" (very formal, archaic)
• "May I come in?" ✓ (normal, polite)
• "Might I come in?" (overly formal, old-fashioned)

Indirect Questions:

• "Do you think she may come?" (fairly likely)
• "Do you think she might come?" (less likely)
• "Could this may be the answer?" (incorrect - use "be")
• "Could this be the answer?" (correct)

May/Might Not - Negatives:

May Not:

• "It may not rain." (probably won't, but possible)
• "She may not agree." (fairly likely she won't)
• "You may not leave." (prohibition - not allowed)
• "This may not work." (decent chance it won't)

Might Not:

• "It might not rain." (probably won't)
• "She might not agree." (less likely to agree)
• "I might not go." (probably won't, tentative)
• "This might not be a good idea." (uncertain, doubtful)

Note: "May not" for prohibition is more forceful than for possibility. Context determines meaning.

May Well / Might Well - Emphasis:

May Well (Quite Likely):

• "She may well be right." (quite possibly right)
• "This may well be true." (very possibly true)
• "It may well rain tomorrow." (quite likely)

Might Well (Reasonably Possible):

• "He might well succeed." (reasonably possible)
• "They might well change their minds." (reasonably possible)
• "You might well be correct." (possibly correct)

May/Might as Well - Suggestion:

Practical Suggestion (No Better Alternative):

• "We may as well start now." (might as well, practical suggestion)
• "You might as well tell the truth." (no point hiding it)
• "I may as well go home." (nothing better to do)
• "We might as well try." (worth attempting)

Note: "May as well" and "might as well" are interchangeable in this usage.

Formal vs Informal Usage:

Formal (Written):

• "Applicants may submit forms online." (formal permission)
• "Changes may occur without notice." (formal possibility)
• "Residents may not sublet apartments." (formal prohibition)

Informal (Spoken):

• "Can I go now?" (more common than "May I?")
• "It might rain." (casual possibility)
• "I might go to the party." (informal possibility)
• "You can't park there." (more common than "You may not")

Note: In modern informal English, "can" often replaces "may" for permission, though "may" remains more polite and formal.

Practice Exercises

Exercise 1: Choose "may" or "might" based on likelihood

1. "The sun _____ come out later." (fairly likely - weather forecast says 70% chance)
2. "I _____ win the lottery." (very unlikely)
3. "She _____ be at home now." (good chance - she usually is at this time)
4. "Aliens _____ exist somewhere in the universe." (possible but uncertain)
5. "The package _____ arrive today." (tracking says it's out for delivery)
6. "I _____ go skydiving someday." (just thinking about it, uncertain)
7. "This medicine _____ cause drowsiness." (common side effect)
8. "I _____ become president one day." (very unlikely, just dreaming)

Answers: 1) may, 2) might, 3) may, 4) might, 5) may, 6) might, 7) may, 8) might

Exercise 2: Permission vs Possibility

9. "_____ I borrow your pen?" (asking permission)
10. "It _____ rain tomorrow." (50% possibility)
11. "Students _____ not use calculators on this test." (prohibition)
12. "You _____ leave when you're finished." (granting permission)
13. "He _____ be at the library." (possibility, but not sure)
14. "_____ I ask you a question?" (polite permission request)

Answers: 9) May, 10) may/might, 11) may, 12) may, 13) might, 14) May

Exercise 3: Conditional sentences

15. "If I were you, I _____ apologize." (conditional advice)
16. "If she called, I _____ answer." (hypothetical)
17. "If I had more money, I _____ travel more." (hypothetical)
18. "If we left now, we _____ catch the bus." (hypothetical possibility)

Answers: 15) might, 16) might, 17) might, 18) might

Exercise 4: Past forms

19. "She said she _____ come to the party." (reported speech)
20. "I _____ have left my keys at home." (uncertain past)
21. "He _____ have been there yesterday." (very uncertain about past)
22. "They _____ have missed the train." (fairly possible past event)

Answers: 19) might, 20) might/may, 21) might, 22) may

Exercise 5: Mixed practice

23. "You _____ want to see a doctor." (gentle suggestion)
24. "This _____ be the best solution." (fairly confident)
25. "I _____ be wrong about this." (tentative admission)
26. "Results _____ vary between individuals." (common variation)
27. "We _____ as well give up." (suggestion, no point continuing)
28. "_____ I have your attention, please?" (formal request)

Answers: 23) might, 24) may, 25) might, 26) may, 27) may/might, 28) May

Common Phrases and Expressions

With "May":

• May I...? - asking permission politely
• You may... - granting permission
• May as well - practical suggestion
• That may be - acknowledging possibility
• Come what may - whatever happens
• Be that as it may - nevertheless, regardless
• May the best man win - traditional saying
• May I remind you - polite reminder

With "Might":

• Might as well - practical suggestion (no better option)
• Might I suggest - very polite suggestion
• You might want to - gentle advice
• I might add - adding information
• One might say - hedging statement
• You might think - introducing a point
• As you might expect - unsurprising result
• As you might imagine - predictable situation

Summary

MAY:

• Permission (formal): "May I leave?"
• Higher probability (50-70%): "It may rain"
• Fairly confident possibility
• Present/future focus
• Formal tone
• Think: More likely, More certain

MIGHT:

• Lower probability (30-50%): "It might rain"
• Less confident possibility
• Tentative or doubtful
• Past form of may (in some contexts)
• Conditional sentences: "If I could, I might"
• Polite suggestions: "You might want to..."
• Think: Less likely, More uncertain

Quick Decision Guide:

1. Asking permission? → May I...?
2. Fairly confident it will happen? → May
3. Doubtful or uncertain? → Might
4. Conditional sentence? → Might
5. Gentle suggestion? → Might want to...
6. Formal possibility/permission? → May
7. Tentative or speculative? → Might

Likelihood Scale:

• Will - certain (100%)
• Should - very likely (80-90%)
• MAY - fairly likely (50-70%)
• MIGHT - less likely (30-50%)
• Could - possible (20-40%)

Conclusion

The difference between "may" and "might" primarily involves degree of certainty and context. While both express possibility, may suggests something is more likely to happen (50-70% probability), while might suggests it's less likely or more uncertain (30-50% probability).

For permission, use may in formal contexts: "May I leave early?" In modern informal English, "can" often replaces "may" for permission.

For possibility, choose based on how confident you are:

• More confident/likely → may: "It may rain" (forecast says 60% chance)
• Less confident/likely → might: "It might rain" (just a slight possibility)

For conditional sentences and hypothetical situations, use might: "If I were rich, I might travel the world."

For polite suggestions, might is often gentler: "You might want to reconsider."

Remember: In many cases, both can be grammatically correct, but they convey different degrees of certainty. Choose the one that best reflects how likely you think something is to happen.

Master this distinction, and your English will be more precise and nuanced!