Teach: may / might — May or Might

may / might — May or Might

may and might express supposition, meaning “might do ~,” or permission, meaning “may do ~.”

Basic Rules

Use may / might + the base form of a verb. They have two meanings: ① supposition, “might ~” ② permission, “may ~.” might is a more tentative version of may and is used when the possibility is lower or when making a cautious prediction. It is useful to imagine “may = about 50%, might = about 30–40%.” May meaning permission frequently appears in the polite expression “May I ~?”
The negatives are may not / might not, meaning “might not be ~” or “must not do ~.” For negative permission, May I not ~? is not normally used; another expression is usually preferred.

Points to Note

① might is not the past form of may; it is a tentative expression showing lower possibility or politeness. It is used for present suppositions. To suppose something about the past, use may have + past participle (“might have done ~”): “She may have gone home.” This is covered in greater detail in the latter part of ninth grade and in high school.
② Difference between “May I ~?” and “Can I ~?”: May I is formal and polite, while Can I is casual. Using May I with adults or strangers creates a good impression.
③ Strength of supposition with may / might / must: must (90%) > may (50%) > might (30%) > could (20%). Choose according to your degree of certainty.

Practice

1. Write “He may not come today” using may.
2. Write “May I open the window?” in polite English.
3. Write “She might be busy” as a tentative supposition.