Can, may, and might are common modal auxiliary verbs that can be confusing even if you are fluent in English. A modal auxiliary verb is a verb that adds to the meaning and mood of a sentence. In the following sentences, “go” is the main verb; note how each modal auxiliary verb helps to produce a different meaning.
I can go to the shops.
She may go to the shops.
He might go to the shops.
You might go to the shops.
The sections below discuss how to use these verbs in standard English.
Can and May–Ability and Permission
If your elementary school teachers were like mine, the following rule may have been drilled into your head in English class:
Use can for the ability to do something.
Use may for permission to do something.
May I have this dance? (I seek permission to dance with you.)
I don’t think I can dance, for my shoes pinch my toes. (I’m unable to dance because my toes hurt.)
In most situations, it is acceptable to use can for permission. May is usually reserved for formal writing and speech. As far as I’m concerned, can and may are interchangeable when asking for permission, but may has a polite, urbane tone and ought to be used when appropriate–as in the example above.
May, Might, and Likelihood
May indicates that something is likely. Might conveys more uncertainty than may.
If you don’t tenderize the meat, it may be tough after grilling. (It is likely that the meat will be tough.)
It might even be too tough to chew. (It is possible that it will be too tough to chew, but it is not likely.)
In addition to how likely something is, whether to use may or might also depends on the tense. Use may to express something that is likely now, but use might to express something that was likely in the past.
I think I may run for president. (present tense)
I thought I might run for president. (past tense)
May, Might, and Giving Advice and Suggestions
When you give advice, you use the word “should”, as in “You should see a doctor for that nasty cough”. Sometimes, however, it may be preferable to weaken your tone. For example, if you want to suggest instead of advise, or if you want to recommend something but minimize its importance, use may or might.
You should proofread your essay before submitting it. (advice)
The following are gentler ways to say the same thing:
You may want to proofread your essay before submitting it.
You might proofread your essay before submitting it.