Siebs's law

Siebs's law is a Proto-Indo-European (PIE) phonological rule named after the German linguist Theodor Siebs. According to this law, if an s-mobile is added to a root that starts with a voiced or aspirated stop, that stop is allophonically devoiced.

Compare:

PIE *bʰr̥Hg- > Latin fragor,

but *s-bʰr̥Hg- > PIE *spʰr̥Hg- > Sanskrit sphūrjati.

Discussion

Siebs proposed this law in the Zeitschrift für vergleichende Sprachforschung auf dem Gebiete der indogermanischen Sprachen, as Anlautstudien. Oswald Szemerényi rejected this rule, explaining that it is untenable and cites the contradiction present in Avestan zdī from PIE *s-dʰi "be!" as counterproof. However, the PIE form is more accurately reconstructed as *h₁s-dʰí from *h₁es- (so not an s-mobile) and thus Siebs' law appears to demand that the sibilant and aspirated stop are both adjacent and tautosyllabic, something which is known to only occur in word-initial position in Proto-Indo-European anyway.

Sources

• Collinge, N. E. (1985). The Laws of Indo-European. John Benjamins Publishing Co. ISBN 978-0-915027-75-0.
• Szemerényi, Oswald (1999). Introduction to Indo-European Linguistics. Oxford University Press. ISBN 978-0-19-823870-6.
• Siebs, Theodore (1904). Zeitschrift für vergleichende Sprachforschung auf dem Gebiete der indogermanischen Sprachen.