语言学试题与答案(9)

胡壮麟

meaning of a word, and these feature symbols are usually written in capitalized letters. For example, the word “man” is analyzed as consisting of the semantic features of [+ HUMAN, + ADULT, + ANIMATE, +MALE]

50. How do you distinguish between entailment and presupposition in terms of truth

values?

Entailment is a relation of inclusion. Suppose there are two sentences X and Y: X: He has been to France.

Y: He has been to Europe.

In terms of truth values, if X is true, Y is necessarily true, e.g. if he has been to France, he must have been to Europe.

If X is false, Y may be true or false, e. g. if he has not been to France, he may still have been to Europe or he has not been to Europe. If Y is true, X may be true or false, e.g. if he has been to Europe, he may or may not have been to France.

If Y is false, X is false, e.g. If he has not been to Europe, he cannot have been to France.

Therefore we conclude that X entails Y or Y is an entailment of X.

The truth conditions that we use to judge presupposition is as follows:

Suppose there are two sentences X and Y:

X: John's bike needs repairing.

Y: John has a bike.

If X is true, Y must be true, e.g. if John's bike needs repairing, John must have a bike. If X is false, Y is still true, e. g. If John's bike does not need repairing, John still has a bike. If Y is true, X is either true or false, e.g. if John has a bike, it may or may not