science

Time flies like an arrow; fruit flies like a banana

Time flies like an arrow; fruit flies like a banana is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Time flies like an arrow; fruit flies like a banana rather than just read about it. In short: "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 and antanaclasis. Analysis of the basic ambiguities The point of the example is that the correct parsing of the second sentence, "fruit flies like a banana", is not the one that the reader starts to build, by a…

Key takeaways

Time flies like an arrow; fruit flies like a banana belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Time flies like an arrow; fruit flies like a banana to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Time flies like an arrow; fruit flies like a banana from memory before moving on to harder problems.

Reference excerpt

"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 and antanaclasis.

Analysis of the basic ambiguities The point of the example is that the correct parsing of the second sentence, "fruit flies like a banana", is not the one that the reader starts to build, by assuming that "fruit" is a noun (the subject), "flies" is the main verb, and "like" as a preposition. The reader only discovers that the parsing is incorrect when it gets to the "banana". At that point, in order to make sense of the sentence, the reader is forced to reparse it, with "fruit flies" as the subject and "like" as the main verb. The first sentence predisposes the reader towards the incorrect parsing of the second. After reparsing the second, it becomes clear that the first sentence could be re-parsed in the same way. The sentence "time flies like an arrow" is in fact often used to illustrate syntactic ambiguity. Modern English speakers understand the sentence to unambiguously mean "Time passes fast, as fast as an arrow travels". But the sentence is syntactically ambiguous and alternatively could be interpreted as meaning, for example:

(as an imperative) Measure the speed of flies as you would measure the speed of an arrow—i.e. (You should) time flies as you would time an arrow. (imperative) Measure the speed of flies using methods that an arrow would use—i.e. (You should) time flies in the same manner that an arrow would time them. (imperative) Measure the speed of flies with qualities resembling those of arrows—i.e. (You should) time those flies that are like an arrow. (declarative, i.e. neutrally stating a proposition) Certain flying insects, called "time flies", enjoy an arrow. 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". Moreover, "Time flies" could refer to "flies of the Time magazine", or "flies of the Pink Floyd song Time". Indeed, a copy of the magazine or the song could also be the subject doing the flying. Furthermore, "like" as a verb could either signify general enjoyment, or the usage of a like button.

History 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:

Flies Around Scoutmaster: Time flies. Smart Tenderfoot: You can't. They go too fast. 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. A fuller exposition with the banana example appeared in a 1966 article by Oettinger. This article prompted the following response in a letter:

Time Flies Like an Arrow An Ode to Oettinger

— Edison B. Schroeder (1966)

The verse is popular as a specimen of didactic humor trading on syntactic ambiguity. Like the poem "The Chaos" by Gerard Nolst Trenité, its themes are popular among practitioners and students in fields such as natural language processing and linguistics.

Other attributions The saying is sometimes attributed to Groucho Marx, but according to The Yale Book of Quotations, there is no reason to believe Marx actually said this. Instead, it traces the Marx attribution to a post from July 9, 1982, on the Usenet group net.jokes; however, the closest match in the Google Groups archives is really dated to September 8, and does not mention Marx.

Use in linguistics The saying is used as a linguistic example of antanaclasis, the stylistic trope of repeating a single word, but with a different meaning each time. It is also used as an example of punning. The wordplay is based on the distinct meanings of the two occurrences of the word flies (the verb "travel through the air" and the noun for certain insects), and of the word like (the preposition "similarly to" and the verb "enjoy"). For example, the second clause can be read as "fruit travels through the air similar to a banana" or as "certain insects enjoy a banana". This is an example of a garden-path sentence, a phrase that the reader or listener normally begins to parse according to one grammatical structure, and is then forced to back up and reparse when the sentence ends in an unexpected way.

See also List of linguistic example sentences Amphibology Antanaclasis Arrow of time Paraprosdokian Perverb Sentence processing Syntactic ambiguity

References

Illustrations

Worked examples

Example 1 — a first encounter with Time flies like an arrow; fruit flies like a banana

Start with the simplest possible case. Write down what Time flies like an arrow; fruit flies like a banana claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Time flies like an arrow; fruit flies like a banana before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Time flies like an arrow; fruit flies like a banana ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Time flies like an arrow; fruit flies like a banana

In research: Time flies like an arrow; fruit flies like a banana appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Time flies like an arrow; fruit flies like a banana in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Time flies like an arrow; fruit flies like a banana is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ambiguity, English phrases, Linguistic example sentences, so understanding it makes those chapters shorter.
In everyday life: Look for Time flies like an arrow; fruit flies like a banana outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Time flies like an arrow; fruit flies like a banana in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Time flies like an arrow; fruit flies like a banana means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Time flies like an arrow; fruit flies like a banana out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Time flies like an arrow; fruit flies like a banana in simple terms?

Why does Time flies like an arrow; fruit flies like a banana matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Time flies like an arrow; fruit flies like a banana?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Time flies like an arrow; fruit flies like a banana.