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At this point, we meet one of the features of modal verbs that often causes difficulty; many modal verbs have more than one meaning or use, and in some cases two different modal verbs have some meanings or uses in common, but are not fully interchangeble. For practical purposes, student need learn only the more inportant distinctions. A fuller description may be found in the reference books. 1 A fuller description can/may be found in the reference books listed at the beginning of this book. In this sentence, can and may are fully interchangable, may being a little more formal. 2 Agreement between management and unions may be reached tomorrow. Assuming we wish to state a possibility rather than a fact, only may is appropriate in this sentence, which means 'It is possible that agreement will be reached'. The distinction between sentences 1 and 2 may be paraphrased as: (1) It is possble for this to be done at any time ( = statement of present fact) (2) It is possbile that this will be done ( = statement of future possibility) Might reporesents the tentative form of may as used in sentence 2:
Could (often stressed) is quite commonly used as an alternatibe to tentatibe might, as in 3a and 3b. Could is not used in this way, however, in affirmative negative sentences: 4a They may (or might) not reach agreement tomorrow. 4b They could not reach agreement tomorrow. These sentences have quite different meanings, because of the way the negative particle not operates. In affirmative sentences with may or might (in the sense of possibility), not goes with the main verb: They may/might not reach agreement tomorrow = It is not possible that they will reach agreement. In this sentence, moreover could operates in a conditional context: 'They could not reach agreement tomorrow, (e.g.) even if they sat talking all day.' |