Sievers's law

the principle in physical metallurgy

Sievers's law in Indo European linguistics accounts for the pronunciation of a consonant cluster with a glide ( or ) before a vowel as it was affected by the phonetics of the preceding syllable. Specifically, it refers to the alternation between and , and possibly and as conditioned by the weight of the preceding syllable. For instance, Proto Indo European (PIE) became Proto Germanic *harjaz, Gothic harjis "army", but PIE became Proto Germanic *hirdijaz, Gothic hairdeis "shepherd". It differs from ablaut in that the alternation has no morphological relevance but is phonologically context sensitive: PIE followed a heavy syllable (a syllable with a diphthong or long vowel, or ending in more than one consonant), but would follow a light syllable (a short vowel followed by a single consonant).

This situation was first noticed by the Germanic philologist Eduard Sievers (1859 1932), and his aim was to account for certain phenomena in the Germanic languages. He originally discussed only in medial position. He also noted, almost as an aside, that something similar seemed to be going on in the earliest Sanskrit texts. Thus in the Rigveda dāivya "divine" actually had three syllables in scansion (dāiviya ) but satya "true" was scanned as written.

After Sievers, scholars would find similar alternations in Greek and Latin, and alternation between and , though the evidence is poor for all of these. Through time, evidence was announced regarding similar alternations of syllabicity in the nasal and liquid consonants, though the evidence is extremely poor for these, despite the fact that such alternations would have left permanent, indeed irreversible, traces. For example, the Sanskrit "tool suffix" tra (e. g. pā tra "drinking cup, vessel") almost always follows a consonant or long vowel and should have therefore been tira ; but no such form as **pōtira , either written as such or scanned thus, is actually attested in the Rigveda or any other Indic text. How a nearly universal suffix ** tira would have been, or even could have been, uniformly replaced by tra is unobvious.

The most ambitious extension of Sievers's law was proposed by Franklin Edgerton (1885–1963) in a pair of articles in the journal Language ( and ). He argued that not only was the syllabicity of prevocalic consonants by context applicable to all six Indo European sonorants , it was applicable in all positions in the word. Thus a form like "sky" would have been pronounced like this only when it happened to follow a word ending with a short vowel. Everywhere else it would have had two syllables, Edgerton also maintained that the phonotactic rules in question applied to sequences arising across morpheme boundaries, such as when the bahuvrīhi prefix occurred before a noun beginning with (e. g. "well heroed", Vedic suvīra ). According to Edgerton, the word should have had two forms, depending on what immediately preceded it: and This corollary he called the "converse" to Sievers's law, and is usually referred to as Edgerton's converse for short. The evidence for alternation presented by Edgerton was of two sorts. He cited several hundred passages from the Rigveda, which he claimed should be rescanned to reveal hitherto unnoticed expressions of the syllable structure called for by his theory. But most forms show no such direct expressions; for them, Edgerton noted sharply skewed distributions that he interpreted as evidence for a lost alternation between syllabic and nonsyllabic consonants (commonly called "semivowels" in the literature). Thus say śiras "head" (from ) has no monosyllabic partner **śras (from ), but Edgerton noted that śiras occurred 100% of the time in the environments where his theory called for the syllabification of the Appealing to the "formulaic" nature of oral poetry, especially in tricky and demanding literary forms like sacred Vedic versification, he reasoned that this was direct evidence for the previous existence of an alternant , on the assumption that when (for whatever reason) this *śras and other forms like it came to be shunned, the typical collocations in which they would have (correctly) occurred inevitably became obsolete at the same time as the loss of the form itself. And he was able to present a sizeable body of evidence in the form of these skewed distributions in both the 1934 and 1943 articles. Edgerton's claims were immediately hailed by many in the scholarly community and enjoyed the status of orthodoxy among Indo Europeanists for 35 or 40 years; in recent times they have not fared so well. Parenthetically, many of Edgerton's data on this point are inappropriate: current scholarship takes śiras, for example, to be the regular reflex of PIE , the syllabicity of the resonant resulting from the fact that it was followed by a consonant in Proto Indo European; there never was, nor could have been, a form to yield Indic **śras. How it might be that a form that is irrelevant to Edgerton's theory might seem to "behave" in accord with it is explained below.

In 1965, Fredrik Otto Lindeman (1936–) published an article proposing a significant modification of Edgerton's theory. Disregarding Edgerton's evidence (on the grounds that he was not prepared to judge the niceties of Rigvedic scansion) he took instead as the data to be analyzed the scansions in Hermann Grassmann's Wörterbuch zum Rig Veda From these he concluded that Edgerton had been right, but only up to a point: the alternations he postulated did indeed apply to all sonorants; but in word initial position, the alternation was limited to forms like "sky", as cited above – that is, words where the "short" form was monosyllabic.

Edgerton's claims, once very generally hailed, have not fared well. Regarding the skewed distributions in the Rigveda, Edgerton neglected to test his observations against controls, namely forms not susceptible to his theory but sharing other properties with the "test" forms such as part of speech, metrical configuration, and so on. The first scholar to look at controls was Franklin Eugene Horowitz (, but whose work actually dates from ten years earlier). Horowitz noted that for example all 65 occurrences of Vedic suvīra "well heroed" do occur in line initial position or follow a heavy syllable (as if in accord with Edgerton's converse), but exactly the same thing is true of e. g. supatrá "having beautiful wings" (which can have nothing to do with Edgerton's law). And indeed such skewing in distribution is pervasive in Vedic vocabulary: śatam "100", and dozens of other forms with no bearing on Edgerton's law, have exactly the same strong preference for not following a word ending with a short vowel that e. g. śiras "head" does, presumably by reason of beginning with a single consonant followed by a light syllable. A second difficulty has emerged much more recently : The actual passages from the Rigveda cited in Edgerton's two large articles in 1934 and 1943 as examples of the effects of his theory in action seriously misrepresent the facts in all but a handful of cases. No more than three Rigvedic passages cited in the 1934 article, and none at all in 1943, actually support the claims of Edgerton's law regarding word initial sequences. This lies well within the operation of pure chance. And it has been shown also that the apparent success of Lindeman's more modest claims are not without troubling problems, too, such as the limitation of the reliable examples to semivowels (the glides and ) even though such alternations in the other four consonants should have left robust outcomes (for example, a disyllabic form of prá "forth, away" should have been very much more frequent than the monosyllable, which would have occurred only after a word ending in a short vowel; but there is no evidence for such a disyllabic form as **pirá, in Vedic or any other form of Indic); and that the syllabified alternants (e. g. ) are very much rarer than they should be: they account for only fifteen to twenty percent of the total: they should account for at least eighty percent, since the monosyllabic form would have originally occurred, like prá, only after a word ending in a short vowel. Further, only the alternants have a "distribution": the shapes show no sensitivity to phonetic environment at all. (And even that disyllabic "distribution" can be inexplicable: disyllabic dyāus in the Rigveda always and only, with one exception, occurs in line initial position, i. e., in only one of the four environments calling for syllabification of the resonant. Nothing in Lindeman's theory accounts for this striking distribution.)