From Wikipedia, the free encyclopedia

Brugmann's law, named for Karl Brugmann, states that Proto-Indo-European *o (the ablaut alternant of *e) in non-final syllables became *ā in open syllables (syllables ending in a single consonant followed by a vowel). Everywhere else the outcome was *ǎ, the same as the reflexes of PIE *e and *a. The rule seems not to apply to "non-apophonic *o", that is, *o that has no alternant, as in *poti- "master, lord" (thus Sanskrit pati-, not *pāti (there being no such root as *pet- "rule, dominate")). Similarly the form traditionally reconstructed as *owis "sheep" (Sanskrit ǎvi-), which is a good candidate for re-reconstructing as *h₃ewi- with an o-coloring laryngeal rather than an ablauting o-grade.

The theory accounts for a number of otherwise very puzzling facts. Sanskrit has pitaras, mātaras, bhrātaras for "fathers, mothers, brothers" but svasāras for "sisters", a fact neatly explained by the traditional reconstruction of the stems as *-ter- for "father, mother, brother" but *swesor- for "sister" (cf. Latin pater, māter, frāter but soror; note, though, that in all four cases the Latin vowel in the final syllable was originally long). Similarly, the great majority of n-stem nouns in Indic have a long stem-vowel, such as brahmāṇas "Brahmins", śvānas "dogs" from *k'wones, correlating with information from other Indo-European languages that these were actually on-stems. But there is one noun, ukṣan- "ox", that in the Rigveda shows forms like ukṣǎṇas "oxen". These were later replaced by "regular" formations (ukṣāṇas and so on, some as early as the Rigveda itself), but the notion that this might be an *en-stem is supported by the unique morphology of the Germanic forms, e.g. Old English oxa nom.singular "ox", exen plural—the Old English plural stem (e.g., the nominative) continuing Proto-Germanic *uχsiniz < *uχseniz, with two layers of umlaut. As in Indic, this is the only certain Old English n-strem that points to *en-vocalism rather than *on-vocalism. (Some additional jickering is necessary to account for the Old English details, but nothing serious.)

Perhaps the most startling confirmation comes from the inflection of the perfect tense, wherein a Sanskrit root like sad- "sit" has sasada for "I sat" and sasāda for "he, she, it sat". It was tempting to see this as some kind of "therapeutic" reaction to the falling-together of the endings *-a "I" and *-e "he/she/it" as -a, but it was troubling that the distinction was found exclusively in roots that ended with a single consonant. That is, dadarśa "saw" is both first and third person singular, even though a form like ¢dadārśa is perfectly acceptable in terms of Sanskrit syllable structure. This mystery was solved when the ending of the perfect in the first person singular was reanalyzed as *-h₂e, that is, beginning with an a-coloring laryngeal: that is, at the time Brugmann's Law was operative, a form of the type *se-sod-h₂e in the first person did not have an open root syllable. A problem (minor) for this interpretation is that roots that pretty plainly must have ended in a consonant cluster including a laryngeal, such as jan- < *ǵenh₁- "beget", and which therefore should have had a short vowel throughout (like darś- "see" < *dorḱ-), nevertheless show the same patterning as sad-: jajana 1sg., jajāna 3sg. Whether this is a catastrophic failure of the theory is a matter of taste, but after all, those who think the pattern seen in roots like sad- have a morphological, not a phonological, origin, have their own headaches, such as the total failure of this "morphological" development to include roots ending in two consonants. And such an argument would in any case cut the ground out from under the neat distributions seen in the kinship terms, the special behavior of "ox", and so on.

Perhaps the most worrisome data are adverbs like Sankrit prati, Greek pros (< *proti) (meaning "motion from or to a place or location at a place", depending on the case of the noun it governs) and some other forms, all of which appear to have ablauting vowels. They also all have a voiceless stop after the vowel, which may or may not be significant. And for all its charms, Brugmann's Law has few supporters nowadays (even Brugmann himself eventually gave up on it, and Jerzy Kuryłowicz, the author of the brilliant insight into the sasada/sasāda matter, eventually abandoned his analysis in favor of an untenable appeal to the agency of marked vs unmarked morphological categories. Untenable because, for example, it's a commonplace of structural analysis that 3rd person singular forms are about as "unmarked" as a verb form can be, but in Indic it is the one that "gets" the long vowel, which by the rules of the game is the marked member of the long/short opposition).

There is an interesting ancillary argument. The structure of the Proto-Indo-European vowel system is highly puzzling. The workhorse vowels are *e and *o; the low-back unrounded vowel *a — NOT counting those attributable to the action of laryngeals—has a decidedly minor role, and seems not to alternate with other vowels at all. This marginal status of *a is very odd in terms of the normal makeup of vowel systems, for all the fact that the reconstruction is absolutely solid. But what if the real source of the familiar and ubiquitous e/o alternation was originally an alternation of a more familiar type, say between *a and *ā. In many, maybe most, languages with vowel length contrasts, there is little if any difference in cavity features between /a/ and /ā/, but in lots of languages there is a difference, typically one or the other will become somewhat front, while (by a polarizing innovation) the other will become backer or even rounded. In Hungarian, for example, /a/ is phonetically [ɔ], while /ā/ is phonetically [ɑ:]; in Persian it is the other way around: /a/ is [æ] and /ā/ is [ɔ:]. If Pre-Proto-Indo-European were actually a language of the Persian sort, it is an attractive notion that as the cavity features of vowels were more or less collapsing in Pre-Indo-Iranian, in one favorable environment (open syllables) the feature of length that had been originally definitive for **/ā/ might have survived. (Note: "short" vowels can be long within a phonology; in most dialects of English, /æ/ and /ɔ/, as in brad and broad are decidedly tense (peripheral) and prolonged and even, in a variety of dialects, undergo various kinds of breaking of a sort that are (a) characteristic of long vowels and (b) not seen in any other "short" vowel in English.)