What is the difference between ‘may’ and ‘might’? Are these words interchangeable? Can the terms ‘may have’ and ‘might have’ be used interchangeably? (Sheela, Chennai)
For learners of English as a foreign language the use of ‘may’ and ‘might’ can be quite confusing, especially when they try to know the difference in usage of the two modal verbs. One of the reasons for confusion is that they have been taught that ‘might’ is the past tense of ‘may’ and as a result they fail to notice the usage of these two terms. Look at this example:
A) Clara may visit us this evening.
B) Clara might visit us this evening.
Here ‘might’ is not used as the past tense of ‘may’. Both ‘may’ and ‘might’ convey the idea of possibility. Though they can be used interchangeably ‘might’ expresses less likelihood than ‘may’. ‘Might’, the past tense of ‘may’, is used in indirect speech:
He said, “I may visit New Jersey in June.”
He said that he might visit New Jersey in June.
According to traditional grammarians the present form ‘may’ should be used when talking about a current situation and the past form ‘might’ should be used when talking about an event that happened in the past:
■ Dr Gomez may accept your invitation if he is free. (present tense)
■ The Principal’s secretary might have prepared the convocation address. (past tense)
In modern English, this distinction is not made:
■ Dr Gomez might accept your invitation if he is free. (present tense)
■ The Principal’s secretary may have prepared the convocation address. (past tense)
As the terms ‘may have’ and ‘might have’ express the same level of probability of an action taking place and convey almost the same meaning, they are used interchangeably. Here are more examples from the British National Corpus:
■ Senior staff may have encountered a similar situation before and can contribute to the discussion.
■ It would be futile to speculate what might have been achieved if....
In the sentences above, ‘may have’ and ‘might have’ are interchangeable.
According to http://www.oxforddictionaries.com , there is a distinction between ‘may have’ and ‘might have’ in certain contexts. If the truth of a situation is not known at the time of speaking or writing, either of the two is acceptable:
■ By the time you read this, he may have made his decision.
■ I think that comment might have offended some people.
If the event or situation referred to did not in fact occur, it’s better to use might have:
■ The draw against Italy might have been a turning point, but it didn’t turn out like that.