Why *p>*f?

[Larry Trask]

On Thu, 28 Jan 1999 X99Lynx at aol.com wrote:

> That brings up a question that has been bothering me for a while. We
> know the rule PIE *p > P-German *f.  As in eg "five" -
> *penkwe>*fimfi (or as in pisce>fish). Now I take that to be a found
> or discovered rule.

Yes.  It is a historical occurrence which linguists discovered.

> In other words, there is nothing in linguistics
> that demands this particular sound change in and of itself.

Absolutely correct.

> It's just acknowledged to have happened that way very consistently
> between the two languages then and afterwards in a whole set of
> instances.

More precisely, */p/ changed to /f/ in an ancestor of all the Germanic
languages in most (not all) circumstances, but remained /p/ in most (not
all) other IE languages.  We can't tell if /p/ changed to [f]
simultaneously in all words, or only gradually, a few words at a time.
The traditional view endorses the first, but many linguists today would
put their money on the second.

> So not as a linguistic matter, but as a matter of "external forces,"
> why *f? Why not *b or *bh or *pw or any other approximate sound or
> why not just stick with *p?

It is not possible to answer questions like these.  If *anything*
happens to /p/ in a language, we know from experience that it's more
likely to change to /f/ or /h/ than to, say, /bh/ or /m/ or /k/.
But we can't predict that a change will happen at all, and we can't
predict which particular change will happen.  Language change is far too
contingent and far too social.

In High German, providing we follow the traditional view, and not
Vennemann's bifurcational theory, */p/ changed to /pf/ -- an
extraordinary development, rarely if ever seen elsewhere.

> (And if it was caused by a group rearrangement of sounds, then what
> external forces caused that particular rearrangement?)

This change was part of a much larger set of systematic changes commonly
called `Grimm's Law'.  But there is no reason to suspect any "external
forces".

> Was it contact with a third language?

Possible, but unlikely.  Anyway, having no knowledge of any such "third
language" (second language, actually), we cannot usefully explore this
possibility.  Anyway, */p/ changed to /f/, */b/ changed to /p/, and
*/bh/ changed to /b/, and what kind of second language could have that
kind of effect?  Germanic had /p/ and /b/ before the changes, and it had
/p/ and /b/ after the changes, so you can't "explain" the changes by
appealing to an unknown language which lacked /p/ or /b/.

> Was it a physical characteristic, the lips, say, of the people who
> made the change?

*Certainly* not.

> Was it a factor of the weather?

Even more certainly not.

> Was it religious or neurological?

Absolutely not.

> Was it random and is that a good enough explanation?

We don't use the word `random'.  If we could observe the change in
progress, we would *probably* find that a handful of people began
pronouncing /p/ as [f], that some other people started to copy them for
some social reason, and that finally everyone was using the new
pronunciation.  This is the way most language changes appear to proceed
when we get the chance to watch them happening.

Larry Trask
COGS
University of Sussex
Brighton BN1 9QH
UK

larryt at cogs.susx.ac.uk