For example:

fourteen, sixteen, seventeen, eighteen, nineteen

These are all number+teen.

What is wrong with threeteen and fiveteen? Why are 13 and 15 written "differently"? Are they coming from third+teen and fifth+teen? If so, why were d and h removed? What is a "thir" and a "fift"?

I am utterly puzzled.

(not to mention eleven and twelve, which could have been oneteen and twoteen, but has been addressed here)

  • 2
    It's from Old English thrēotīene (see three, -teen). The spelling with initial thi- is recorded in late Middle English. Also, Middle English thrittene, from thrittene, adjective, from Old English thrēotīne; akin to Old English tīen ten – marcellothearcane Jul 6 '17 at 11:16
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    Do not ask why any words evolved thus; our forefathers spoke these words in certain ways which became a language, and it has come down to us in this form. It will change in future. Nobody held a conference in the year 1596 / 1796 / 1996 to formalise the words of the English language. In fact at least a few other languages seem to have undergone formal revisions but as @Hot Licks said, this is English! – English Student Jul 6 '17 at 11:42
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    If you expect consistency, surely it should be onety-one onety-two onety-three etc..? – JeffUK Jul 6 '17 at 12:17
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    Personally I think this is a fine question. The question about eleven and twelve was on topic and highly upvoted, why shouldn't this be on topic as well? It's probably a commonly searched question online, EL&U could provide an answer to those folks. – RaceYouAnytime Jul 6 '17 at 12:46
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    Etymonline is a good starting place to see where words come from. It's fairly common for sounds to change positions in a word; there's even a name for it, metathesis. – Jacinto Jul 6 '17 at 18:06

It has always seemed obvious to me: Three-teen and five-teen are harder to say than thirteen and fifteen. People are lazy.

The rest, laziness really doesn't make the pronunciation easier metathesis does not seem as natural.

(And, really, it would be the same with third and fifth. Try saying, once, tooth, threeth, fourth, fiveth.)


Some people will note the middle English "fifthe", and object, but I'll point out that the cardinal is voiced as far back as middle English. You have to go back to old English to get an unvoiced "fif" as the cardinal number, and then you have to ask why middle English became voiced only in the cardinal.

It is true that the obvious always assumes the current context, but the current context is derived from the old context, and the principle of laziness applies in the old context at least as much as it applies now.

(end afterthought)

(second afterthought)

I am doing too much reading between the lines in the above.

Here is the entry for thirteen in the Online Etymology Dictionary:


Summary: it was spelled "thrittene" in Middle English, and shifted (metathesis) in the late 14th century. While the metathesis is recorded, the cause or reason is not. (How can we travel back in time and take a survey?)

Asserting laziness is probably oversimplifying. The impulse to change things for the sake of change is also a probable cause, and there are other known causes as well, such as linguistic fashion. Different people would have had different reasons, and the generalization of the metathesis is a statistical event, a "summation of many reasons.

So I'll apologize for asserting laziness.

fifteen and five in the Online Etymology Dictionary,

and five in Wiktionary

Note that five was five in Middle English, but fif in Old English. This is not metathesis, but the causes of the pronunciation change are not clearly stated in the above or anything else I have handy today. (I should check the Online Oxford, but it's one in the morning. I have other things I should be doing.)

(end second afterthought)

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  • 3
    But what is "obvious" is generally wrong. – Carl Witthoft Jul 6 '17 at 14:52
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    Do you have a reference to show that the obvious is wrong in this case? If so, please post it. – Joel Rees Jul 6 '17 at 14:57
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    Joel, that is not how things work. You have made a claim; it's up to you to validate it. It is not up to the rest of us to invalidate it. (See "god exists" for the usual example of your false logic) – Carl Witthoft Jul 6 '17 at 15:00
  • @CarlWitthoft Getting a little closer to definitive? ;-) I'm going to bed. – Joel Rees Jul 6 '17 at 16:08

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