# The etymology of numbers

**URL:** <https://boards.straightdope.com/t/the-etymology-of-numbers/697116>\
**Category:** Factual Questions\
**Created:** [September 1, 2014, 5:51am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116 "2014-09-01T05:51:17Z")\
**Posts on this page:** 12\
**Page:** 1

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**Author:** ![pianodave](https://avatars.discourse-cdn.com/v4/letter/p/e79b87/32.png) [@pianodave](https://boards.straightdope.com/u/pianodave)\
**Post date:** [September 1, 2014, 5:51am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/1 "2014-09-01T05:51:17Z")

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Hi everyone,

Hoping you could help me with an numeric etymology question that’s been bothering me for a couple of weeks now.

A quick Google Search got me 1-10 in Latin:

1 ūnus  
2 duo  
3 trēs  
4 quattuor  
5 quīnque  
6 sex  
7 septem  
8 octō  
9 novem  
10 decem

Now when you have the numbers in English and German, you have one, (eins)  
two (zwei), three (drei), four (vier), five (fünf), six (sechs), seven (sieben), eight (acht), nine (neun) and ten (zehn).

The English and German sets are clearly etymologically related.

So I was thinking: one, two, three, six, seven, eight, nine and ten are easily traceable etymologically to their Latin equivalents.

But what happened to four and five? Why don’t we say something like one two three quart quint or something? Four and five are noticeably far from these quart/quint words. Why did the “q/c” latin root remain in other languages (French: quatre and cinq, Italian: quattro and cinque) but resolve to an F sound in early German? And why just for four and five?

Please help me, I need enlightenment!

Pianodave

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**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\
**Post date:** [September 1, 2014, 6:28am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/2 "2014-09-01T06:28:25Z")

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English numbers aren’t derived from Latin; they’re both derived from a common Indo-European root.

The Proto-Indo-European version of five is \*penkwe; the evolution of the initial /p/ to an /f/ in English is quite regular. It’s Latin (and its descendants) which seems the anomaly here; I don’t know how to explain the evolution into “quinque”.

As for four, here the Proto-Indo-European is \*kwetwer. For what it’s worth, the Online Etymology Dictionary says “The phonetic evolution of the Germanic forms has not been fully explained; Watkins explains the -f- as being from the following number (Modern English five)”, which seems odd to me, but there you go.

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**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\
**Post date:** [September 1, 2014, 6:37am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/3 "2014-09-01T06:37:06Z")

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> [@Indistinguishable](#):
>
> The Proto-Indo-European version of five is \*penkwe; the evolution of the initial /p/ to an /f/ in English is quite regular. It’s Latin (and its descendants) which seems the anomaly here; I don’t know how to explain the evolution into “quinque”.

I think the standard hypothesis is that the /p/ assimilated to /k[SUP]w[/SUP]/, as in Latin ‘coquina’ \< PIE \*pek[SUP]w[/SUP]- (but apparently without the labialization).

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**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\
**Post date:** [September 1, 2014, 6:48am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/4 "2014-09-01T06:48:19Z")

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Ah, I see. Some Googling reveals Latin ‘quercus’ \< PIE \*perk[sup]w[/sup]u to be another example of such assimilation.

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**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\
**Post date:** [September 1, 2014, 6:57am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/5 "2014-09-01T06:57:32Z")

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Forgot to mention: Latin ‘novem’ (9) was originally ‘noven’ \< PIE \*neun, but apparently changed by analogy with ‘septem’ \< PIE \*septm and ‘decem’ \< PIE \*dekm or \*dekmt. It’s at least not implausible that the same thing happened with 4 and 5. (I also wonder how a mouthful like \*k[SUP]w[/SUP]etwores got used for such a small number.)

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**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\
**Post date:** [September 1, 2014, 8:36am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/6 "2014-09-01T08:36:49Z")

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As others implied, “five” and “cinco” are actually cognate(!!) via a series of sound changes. I think a key point is that the two consonants in /penkwe/ transformed by assimilation in two different ways (followed later by _p \> f_ in Germanic and _k \> s_ in some Romance languages).

(“Assimilation: sounds become more like neighboring sounds, allowing for ease of articulation or pronunciation”) To see why assimiliation was “desirable” for /penkwe/, try counting fast-moving animals: one, two, three, four, penkwe, six. … 😉

The Indo-European 7 /septm/ was borrowed from Semitic. Was this because the ancestors of the I-E people counted only to 6, or because the Semites had an influential reverence for the number 7? The Semitic word for Seven and the Hebrew word for Sabbath are not considered to be cognate, but I wonder if they are.

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**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\
**Post date:** [September 1, 2014, 10:20am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/7 "2014-09-01T10:20:07Z")

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Here are the numbers in Proto-Indo-European and a variety of Indo-European languages (and, at the end, some non-Indo-European ones):

[http://www.zompist.com/euro.htm](http://www.zompist.com/euro.htm)

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**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\
**Post date:** [September 1, 2014, 12:51pm UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/8 "2014-09-01T12:51:44Z")

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> [@Itself](#):
>
> I think the standard hypothesis is that the /p/ assimilated to /k[SUP]w[/SUP]/, as in Latin ‘coquina’ \< PIE \*pek[SUP]w[/SUP]- (but apparently without the labialization).

Curiously, Romanian reverted back to the /p/ in 4 (patru) and 8 (opte). As well as a number of other Latin words where the /q/ was shifted to /p/.

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**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\
**Post date:** [September 3, 2014, 2:07am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/9 "2014-09-03T02:07:29Z")

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> [@jtur88](#):
>
> Curiously, Romanian reverted back to the /p/ in 4 (patru) and 8 (opte). As well as a number of other Latin words where the /q/ was shifted to /p/.

… Curiously Romania is closer to Iran… ?

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**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\
**Post date:** [September 3, 2014, 3:48am UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/10 "2014-09-03T03:48:09Z")

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> [@Isilder](#):
>
> … Curiously Romania is closer to Iran… ?

Closer than what? Uruguay? Can you finish your question, and I’ll take a stab at it.

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**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\
**Post date:** [September 3, 2014, 8:37pm UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/11 "2014-09-03T20:37:50Z")

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It seem pretty clear to me that \*kwetwer lives on in the English quarter (one fourth). Though I suppose that might have come via the Latin quattuor.

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**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\
**Post date:** [September 3, 2014, 9:31pm UTC](https://boards.straightdope.com/t/the-etymology-of-numbers/697116/12 "2014-09-03T21:31:41Z")

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> [@OldGuy](#):
>
> It seem pretty clear to me that \*kwetwer lives on in the English quarter (one fourth). Though I suppose that might have come via the Latin quattuor.

Yes, many words with similar meaning are cognates, undergoing different sound changes due to different borrowing routes.

These English near-synonyms, each with a different initial sound, are all, ultimately, cognates:  
[ul][li] Head \< heafod (OE) \< haubit (Germanic) \< kaput (PIE)[/li][li] Captain \< capitaine (OF) \< capitaneus (L) \< caput (L) \< kaput (PIE)[/li][li] Chief \< chief (OF) \< capum (L) \< caput (L) \< kaput (PIE)[/li][li] Chef \< chef (Modern French) \< chief (OF) \< capum (L) \< caput (L) \< kaput (PIE)[/li][/ul]