In my experience, "finite" is pronounced (IPA) ˈfaɪnaɪt while "infinite" is ˈɪnfɪnɪt.

In general, the prefix "in" negates an adjective, but does not change the pronunciation. Based on this, I would expect ˈɪnfaɪnaɪt.

Is there a reason for this "deviation from the norm"? Are there dialects/regions that actually say ˈɪnfaɪnaɪt (or ˈfɪnɪt, for that matter)?

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    Nitpick: I have /ˈɪnfəˌnɪt/, which I think is usual. (I speak AmE and have a mathematical background.)
    – Charles
    Commented May 5, 2011 at 17:06
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    Double nitpick: depending on your dialect, /ɪ/ may or may not be used in unstressed syllables. This gives either /ˈɪnfɪˌnɪt/ or /ˈɪnfəˌnɪt/. Commented Feb 12, 2012 at 19:30
  • In Christian hymns (of say the Victorian era), the ... /ˈfʌɪnʌɪt/ pronunciation prevailed, and probably still does when they're sung nowadays. Commented Jun 6, 2020 at 11:00
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    Because English.
    – Hot Licks
    Commented Jun 6, 2020 at 12:22

5 Answers 5


I believe we pronounce infinite the way we do because a dactyl is simply easier to say, in most cases. It trips (quite literally) off the tongue. It seems we're forced into the spondee of finite, even though that is harder to say, because nothing else makes sense. But once that extra syllable has come to the rescue we can get lazy again.


After giving the matter more thought, I think we pronounce finite as a spondee because both syllables have the "long i" sound (aɪ). I can't think of a single instance of aɪ coming on an unstressed syllable. I think that's mainly true of all the "long" vowels as well, but I will not be surprised if someone can come up with an exception or three.

  • Assuming this is true, are there other examples of this transformation? Commented Jan 8, 2011 at 12:23
  • @ShreevatsaR: What about the difference between carbonate (as a verb such as: I carbonate my beverages at home) pronounced car-bon-eight and bicarbonate, which I often hear pronounced on television as bi-carb-o-nt (with the stress on the "bi"). It's not as pronounced as the difference between finite and infinite, but I think it can be attributed to the same phenomenon that Robusto is describing.
    – Andy F
    Commented Jan 8, 2011 at 12:37
  • »I think we pronounce finite as a spondee because both syllables have the "long i" sound ().« - Isn't that somewhat begging the question? I'm prepared to take the "lazy" argument, though, apparently it's behind many things that affect the English language.
    – Tomalak
    Commented Jan 9, 2011 at 17:33
  • @Tomalak: "Lazy" is behind EVERY human language, right after "get the message across somehow". Commented Jan 10, 2011 at 16:07
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    @ShreevatsaR I was thinking of insight. It doesn't end on ite, but it's pronounced the same way as dynamite or finite and has the same short in at the beginning as infinite. So if we say ɪnsaɪt, why not also ɪnfaɪnaɪt?
    – Stacky
    Commented Aug 13, 2016 at 13:15

It's the three syllable rule that messes it up. Logically FI-nite would be in-FI-nite with the prefix, but as it becomes three syllables, the third syllable from the end is stressed and it becomes IN-fi-nite. When you stress the first syllable, you have to change the pronunciation to un-stress the second syllable.

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    Why the downvote? If you don't explain what you think is wrong, it can't improve the answer in any way.
    – Guffa
    Commented Jan 8, 2011 at 13:18
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    Edited to correct your spelling of syllable ("syllible") and pronunciation ("pronounciation"). That was probably the basis of the objection.
    – Robusto
    Commented Jan 8, 2011 at 13:30
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    I think the downvote was because this answer doesn't seem to adequately answer the question. Obviously, there is a stress shift. OP is asking why this came about (historical, phonotactic, etc.) and whether there are parallel examples. The question was not what the difference is.
    – Steven
    Commented Jan 8, 2011 at 15:38
  • @Robusto: Thanks for the corrections. The awkward pronunciations of those words keep fooling me... I hope that your theory that this would be the basis of the downvote is not correct.
    – Guffa
    Commented Jan 8, 2011 at 16:44
  • I always have to go back and correct the spelling of "pronounciation". The correct "pronunciation" makes no sense to me at all. ;-) So that three syllable rule is an "official" thing?
    – Tomalak
    Commented Jan 9, 2011 at 17:39

I think Robusto is right that it is related to stress. The stress change causes the unstressed vowel after the prefix to become reduced.

Two stress patterns exist for the prefix in-

You say that "in general, the prefix "in" negates an adjective, but does not change the pronunciation." I would agree with that, but note that normally the prefix in- is also unstressed, even when it is the third syllable from the end : look at the word infertile /ɪnˈfɜrtəl/, which is the negative counterpart to fertile /ˈfɜrtəl/.

So, I think we have to differentiate two versions of the prefix: the more common and productive version in1- does not take stress and does not change the pronunciation; but there is another, rarer prefix in2- that does take stress and may cause other changes in pronunciation. This distinction also applies to some other prefixes, by the way, such as re-, de- and pre (compare definite and deform). Obviously, both versions of the prefix have very similar meanings, and in some cases different speakers may use different versions. But I have not heard of anyone saying /ɪnˈfaɪnaɪt/, so I think this particular word only exists with the prefix in2-.

Here are some more words with in2-:

Some of these are valid words without the prefix, others are not.

Comparing words with and without the prefix, we can see the kind of sound changes it causes:

  • famous /ˈfeɪməs/, infamous /ˈɪnfəməs/
  • potent /ˈpoʊtənt/, impotent /ɪmpətənt/
  • pious /ˈpaɪəs/, impious /ˈɪmpiəs/

The prefix does not only receive stress, it converts the following syllable into a fully unstressed syllable. In English, vowels in unstressed syllables are reduced.

So that explains the difference in the pronunciation of "fin".

The failure of "silent e" after some unstressed syllables

I'm still not sure exactly why there is a difference in the pronunciation of the final syllables of finite and infinite. I haven't found any other pairs of related words like this that alter the pronunciation of the vowel in the last syllable.

There are a few other words that also show a short unstressed "i" before a silent e like this:

  • hypocrite
  • requisite
  • exquisite
  • apocrine

It may be related to having stress on the third-to-last (antepenultimate) syllable. All of these words have this stress pattern, or at least they did originally: nowadays exquisite is often stressed on penultimate.

There are also numerous adjectives and nouns ending in -ate pronounced as /ət/, e.g. associate, delicate, desolate, deliberate, delegate, desperate.

  • This is very systematic and informative, thank you!
    – Tomalak
    Commented Feb 20, 2016 at 23:45

I believe its a matter of stress. IN-fi-nite. FI-nite. It is very awkward to say a word with two stressed syllables followed by one unstressed.

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    But the syllable only appears to you as "stressed" since you are used to interpreting it this way. How would you pronounce Fein (yes, as in "The Nanny")? Does the "FI" it appear to you as stressed there?
    – Tomalak
    Commented Jan 8, 2011 at 11:15
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    Also, this doesn't explain why the word isn't, say, in-FI-nite. Commented Jan 8, 2011 at 11:46
  • And actually, looking for reliable rules in language is futile (and I'm not really sure how you pronounce that ;-)). There's a "Houston Street" in NYC. Guess how that's pronounced ;-) Commented Jan 8, 2011 at 22:47

(cross posted with the very useful link to Pronunciation differences between “finite” and “infinite”)

From OED:

Infinite - Etymology: < Latin infīnītus unbounded, unlimited, < in- (in- prefix3) + fīnītus finite adj. and n.; perhaps originally through Old French infinit, -ite (13th cent. in Hatzfeld & Darmesteter), later infini (Oresme, 14th cent.).

In stark contrast to the word “finite” which (i) has only ever been spelled with a final ‘e’, and (ii) entered the language at least 100 years after “infinite”, the word “infinite” entered English in the 1200s and is often found spelled without the “e”. (The final “e” in French words is not pronounced and does not influence the preceding vowel sound.)

Forms: ME–15 infynyt(e, ME–16 infinit,

(OED) This gives an idea as to the early pronunciation.

Thus we have the separate introduction of finite and infinite into the language with “infinite” entering significantly before “finite”, which is the reverse of what one might expect.

In the Latin, the first “i” was short and the second two long /i:/. In French, the first “i” would have been nasal (a unknown sound in English) and the second two long. However, in English, and without the final “e”, all the vowels are short with the final “i”, through lack of emphasis, reducing to a schwa.

There are two meanings to infinite:

  1. OED Infinite - /ˈɪnfɪnɪt/ A. adj.

1.a. Having no limit or end (real or assignable); boundless, unlimited, endless; immeasurably great in extent, duration, or other respect.


4.b. Of a quantity or magnitude: Having no limit; greater than any assignable quantity or magnitude (opposed to finite). Of a line or surface: Extending indefinitely without limit, and not returning into itself at any finite distance (opposed to closed).


Infinite – /‘inˈfʌɪnʌɪt/ This is occasionally heard and copies the pattern of “non-finite” = /nonˈfʌɪnʌɪt/ and has the meaning of not definite or undefined (Similar to the obsolete meaning of inifinite: †3. Indefinite in nature, meaning, etc.; indeterminate. (OED))

The change in vowel sound is an extension of a change of emphasis used for clarity and to remove ambiguity whilst still conveying the general idea expressed by the root noun.

Similar differences in the vowel sound also are seen in the pronunciation of

Contract – (i) to shorten and (ii) to employ under a contract

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