Time flies like an arrow

"Time flies like an arrow; fruit flies like a banana" is a humorous saying that is used in linguistics as an example of a garden path sentence or syntactic ambiguity, and in word play as an example of punning, double entendre, and antanaclasis.

"Time flies like an arrow" is an English phrase often used to illustrate syntactic ambiguity. In this connection the sentence is often seen as part of the elaboration: "Time flies like an arrow; fruit flies like a banana".

Modern English speakers unambiguously understand the sentence to mean "As a generalisation, time passes in the same way that an arrow generally flies (i.e. quickly)" (as in the common metaphor time goes by quickly). However, the matter is more difficult in the formal interpretation of natural language; formally the sentence is logically ambiguous and alternatively could be interpreted as meaning, for example:

In addition, the sentence contains semantic ambiguity. For instance, the noun phrase "Time flies" could refer to all time flies or particular time flies, and "an arrow" to all arrows, a particular arrow, or different arrows for different flies; compare "Fruit flies like a banana", "Fruit flies ate a banana", "Fruit flies live on a banana". Likewise, the noun "Time" could refer to the magazine.

The expression is based on the proverb: "Time flies", a translation of the Latin Tempus fugit, where "fly" is to be taken in the sense of flee.

An early example of a pun with the expression "Time flies" may be found in a 1930 issue of Boys' Life:

Anthony Oettinger gives "fruit flies like bananas" as contrasted with "time flies like an arrow" as an example of the difficulty of handling ambiguous syntactic structures as early as 1963, although his formal publications with Susumu Kuno do not use that example. This is quoted by later authors.

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