any stretch of talk

grammatically complete string of words expressing a complete thought

part of the meaning of the utterance

A sentence is lexically ambiguous when it can have two or more possible meanings due to polysemous (words that have two or more related meanings) or homophonous (a single word which has two or more different meanings) words.

A sentence is structurally ambiguous if it can have two or more possible meanings due to the words it contains being able to be combined in different ways which create different meanings.

Paraphrases have the same truth conditions; if one is true, the other must also be true.

The boys like the girls’ and ‘the girls are liked by the boys’, ‘John gave the book to Chris’ and ‘John gave Chris the book’.

Each sentence must be true for the other to be true

‘John is married to Rachel’ and ‘Rachel is John’s wife’, ‘Chris is a man’ and ‘Chris is human’.

Only one of the sentences must be true for the other to be true, but that sentence may be true without the other sentence necessarily having to be true.

‘Rachel is John’s wife’ entails ‘John is married’ (but John is married does not entail Rachel being his wife),

Sentences contradict each other when one sentence is true and the other cannot be true

Rachel is an only child’ and ‘Rachel’s brother is called Phil’, ‘Alex is alive’ and ‘Alex died last week’.

what is speaker means

what sentences means

Words are synonymous/ synonyms when they can be used to mean the same thing

Examples: Begin and start, Big and large, Youth and adolescent.

Words are antonyms of one another when they have opposite meanings

again, at least in some contexts). Big and small, Come and go, Up and down.

A word is polysemous when it has two or more related meanings.

Bright (shining) and bright (intelligent). Mouse (animal) and mouse (computer hardware).

Homophony is similar to polysemy in that it refers to a single form of word with two meanings, however a word is a homophone when the two meanings are entirely unrelated.

Bat (flying mammal) and bat (sports equipment). Pen (writing instrument) and pen (small cage).