Introduction to Semantics: Unit 1. (Part I)

Entailment is a relationship between sentences so that if a sentence A entails a sentence B, then if we know A we automatically know B."

• true

• false

Contradiction is a sentence relation where sentences A and B may or may not necessarily be false.

• true

• false

Answer explanation

Contradiction is a sentence relation where "[sentences] A and B are necessarily false".

Saeed; p. 4, 88

Which of the following sentences represents an entailment of the sentence "John gave her a tulip?"

• John gave her a flower.

• John did not give her a flower.

• John did not give her a tulip.

Which of the following sentences represents an entailment of the sentence "John killed a wasp?"

• John regrets that he killed a wasp.

• The wasp is dead.

Answer explanation

"[Entailment is] a relationship between sentences so that if a sentence A entails a sentence B, then if we know A we automatically know B."

"[I]t should be impossible at the same time to assert A and deny B."

Saeed; p. 4

Which of the following sentences represent an entailment of the sentence "All dogs are brown?"

• My dog is brown.

• My dog is black.

• John's dog is brown.

• John's dog is black.

Which of the following sentences represent an entailment of the sentence "This is a dog?"

• This is an animal.

• This is a living creature.

• This is a bird.

Which of the following sentences is contradictory to the sentence "The wasp is dead?"

• The wasp is alive.

• The was is not alive.

Answer explanation

Contradiction is a sentence relation where "[sentences] A and B are necessarily false".

Saeed; pp. 4; 88

Which of the following sentences are contradictory to the sentence "John is still singing?"

• John is no longer singing.

• John is not singing.

• John is singing.

Which of the following sentences are contradictory to the sentence "My brother is a bachelor?"

• My brother is unmarried.

• My brother is married.

• My brother is not unmarried.

• My brother is not a bachelor.

Meanings of the following sentences:

(a) Visiting relatives can be dangerous.

(b) Flying planes can be dangerous.

• entail

• are ambiguous

• contradict

Answer explanation

Two semantic readings for each sentence:

(a)

1. To visit relatives can be dangerous.

2. Relatives that are on a visit can be dangerous.

(b)

1. To fly planes can be dangerous.

2. Planes that fly can be dangerous.