English is a language of synonyms. We inherited words from the Germanic tribes, the Vikings, the French, and the Romans and assimilated words from other cultures as far apart as India and Italy. So it should come as no surprise that subtle variations and nuances between near synonyms cause trouble for even native speakers of the language.
Two such words are the topic of today’s post: “may” and “might.” Both words are auxiliaries (helping verbs) that express some degree of possibility or probability. In some cases, the words can be considered synonyms; in others, they carry different shades of meaning. To make matters more confusing, the past tense of “may” is “might,” a difference that is often ignored even by skilled writers.
“May” indicates either possibility or probability. So does “might,” sometimes. However, “might” is also considered a weaker version of “may,” suggesting a lesser degree of probability. Also, “may” is preferable in cases where the subjunctive would be appropriate, to indicate when the circumstances described are contrary to fact, hypothetical, have not yet happened, or are conjecture rather than actuality.
Examples of each use follow:
It may rain today.
It might rain today.
“May” in the past tense
He is not at work today; he may be sick.
He was not at work yesterday; he might have been sick.
Indicating different degrees of probability
Due to several errors in protocol, the results of your tests may have been compromised.
Due to several errors in protocol, the results of your tests might have been compromised.
In the subjunctive
Because of widespread power outages, her flight may have been canceled.
Likewise, careful writers will make use of the distinction between the words “can” and “may.” The former expresses an ability to do something; the latter grants permission to do so.
“May,” when it grants permission, can be strengthened by its variant “must,” which indicates a requirement or a necessity. The following three sentences indicate the increasing degrees to which these three words can be used:
“Can,” “May,” and “Must”
Visitors can stay at the lodge or at the campground.
Hikers may be accompanied by pets on a 6’ leash.
Thru-hikers must register at the lodge before proceeding into wilderness areas.
These differences are highly contextual. The more formal your writing, the more closely you need to adhere to the rules of grammar and the conventions of style. International audiences will be particularly attuned to the differences, and regulatory writing is likewise sensitive to these nuances. Remember the cardinal rule of writing: when in doubt, look it up!
Michelle Baker is the Conservation Writing Pro. She teaches environmental scientists how to write more clearly, and she edits scientific journal articles and APA dissertations. Contact her for all your writing training and editing needs: email@example.com.