I was wondering if this was technically possible in English. I did not know if there are specific grammar rules that would make an infinite sentence impossible.

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    What is an “infinite sentence”, what is “grammatically correct”, and why do you care? – tchrist May 16 '14 at 1:44
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    Write a sentence in a circle that ends as it began and you've got it. Otherwise, this is just a novelty, and primarily opinion based. – anongoodnurse May 16 '14 at 1:47
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    No, it's not possible. There can be no infinite-length sentence that is correct because it could never be parsed, hence the grammaticality could not be determined. – John Lawler May 16 '14 at 4:12
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    @JohnLawler Smells like you just might be able to reduce that one to the halting problem. :) – tchrist May 16 '14 at 4:48
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    What @medica said. Circular sentences are quit easy to create, and they can be considered infinite, inasmuch as you can simply repeat them over and over without ever creating an ungrammatical sequence—though of course you'll never end up with a complete, finished sentence, either (but that's a side effect of infinity). “How I hate what you said about what he thinks about”, for instance, is recursive and never ends if you start from the top every time you reach the end. – Janus Bahs Jacquet May 16 '14 at 12:54

The answer is no. A sentence needs punctuation. After that punctuation it is over. A sentence fragment can be infinite but not a whole sentence because it has to end.

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    This only seems to apply if you compose the sentence from beginning to end. I could compose "This is a very long sentence." and then add a "very" an infinite number of times. This sentence would have proper punctuation. – DQdlM May 16 '14 at 13:18
  • "A beach can have an infinite coastline but not a whole landmass because it has to be surrounded by water." – nmclean May 16 '14 at 13:23
  • Sentences do not need punctuation. Sentences are spoken, not written. Punctuation is like gasoline; you need it to run the car, but you don't need it to walk. – John Lawler May 16 '14 at 13:31
  • @JohnLawler - I agree but he said to write a sentence. – RyeɃreḁd May 16 '14 at 13:58
  • If it's limited to writing, then grammar and grammatical correctness go out the window (if there's any left to throw by this time). Limiting it to writing reduces it to a rather silly computer game; grammar isn't designed for things like that, any more than humans are designed to fly without machines. This is like asking how far humans could fly if they installed jet engines in their butts. – John Lawler May 16 '14 at 14:44

According to Wikipedia, such a sentence is theoretically possible.

In practice, of course, though the clauses and other structures of even the longest sentence may be notionally separated by such typographical devices as semi-colons, dashes, parentheses and so, in practice that sentence will consist of shorter sentences which might as well be marked off at intervals by full stops/periods as by the various pseudo-periods I've just mentioned.

  • How does a sentence have a shorter sentence in it? Wouldn't that at least be sentences? – RyeɃreḁd May 16 '14 at 5:56
  • @RyeɃreḁd, What about, "How does a sentence have a shorter sentence in it, wouldn't that at least be sentences?" – Ian May 16 '14 at 12:36
  • Good start. Got lost along the way. Think again! :) – Kris May 16 '14 at 13:38

There is no reason that a computer couldn't be coded to write a recursive sentence along the lines of

I wrote down a 1, and then I wrote down a 2, and then I wrote down a 3, and then I wrote down a 4, ...

with a simple k + 1 increase, indefinitely extended. Of course, a machine wouldn't reach infinity with that operation, any more than computers calculating π or simply counting integers ever would.

But more to the point, it's hard to argue that such a sentence has any theoretical interest, since it amounts to a snippet of language infinitely repeated with one minor and predictable variation in each iteration. Is it grammatically correct? Sure. Is it coherent? Enough so that no one would be tempted to spend more than an extremely finite period of time reading it. But so what?

The problem with the most obvious infinitely long sentences is that their trajectory is too boringly easy to comprehend, not that they are overwhelmingly complicated. And the direction of the simple case is enough to persuade me that the undertaking itself isn't very interesting.


A sentence is only grammatically correct if it can be mentally parsed by speakers/readers of the language in question. Even a sentence with 7+ levels of nested clauses fails to be grammatically correct in this sense, so forget about infinite sentences.

  • I agree. I think of the attempts to construct artificially long sentences as akin to trick shots in billiards, especially if they cannot be understood without having to be separately explained. – Erik Kowal May 16 '14 at 15:05

There is no theoretical limit on the length or depth of a sentence. But

  • An infinite sentence cannot be uttered, because the utterer will die before it can be completely encoded, and

  • An infinite sentence cannot be understood, because it cannot definitively decoded until it reaches its end; but a sentence which reaches its end is not infinite.

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    What if the person saying the sentence was traveling faster than the speed of light. Did you even think this thing out properly? – RyeɃreḁd May 16 '14 at 4:11
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    @RyeɃreḁd Then we would have a bigger issue on our hands because ordinary matter cannot travel at the speed of light. – person27 May 16 '14 at 5:53
  • @Stopforgettingmyaccounts... How the hell do you know that? – RyeɃreḁd May 16 '14 at 5:55
  • @RyeɃreḁd Google and current theoretical science, as well as E=MC^2, which states that as your state of energy is greater, it takes exponentially more energy to travel faster. – person27 May 16 '14 at 5:56
  • @Stopforgettingmyaccounts... I bet you that given an infinite amount of time, people will travel faster than the speed of light. – RyeɃreḁd May 16 '14 at 6:00

There are many constructs to generate infinite sentences:

  • I heard that he heard that I heard that he thought that I said that he thought...
  • I said "I said "I said "I said...
  • At the casino, I rolled a 1, then a 2, then a 3, then a 1, then a 5, then a 6...
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    I love the "I said 'I said "I said 'I said...'"'" one. – Joe Z. May 16 '14 at 13:51
  • Then just write one of these on a Mobius strip and there you have it. You can read forever and not hit the end, but it has finite size, just like you can walk on a globe infinitely but not be infinitely far from your start. – Oldcat May 17 '14 at 0:09
  • @Oldcat: All these constructs can be made so that they never repeat, like pi. Without getting too mathy, for each of these verbs you can assign a number. For example, the first one could assign heard to 1, thought to 2, and said to 3. Then just imagine an irrational number written in base 4. That number has a corresponding infinite sentence that can never be written as a repeating sequence a la a Mobius strip. – user66309 May 18 '14 at 16:59
  • @JoeZ. you might enjoy this and this – cat Mar 4 '16 at 3:47

Maybe you could have a sentence that goes on and on and on and on and .... and on and on and on for an infinitely long time and then stops.

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    If it goes "for an infinitely long time," how can it "and then stop?" ;) -- When? – Kris May 16 '14 at 13:40

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