Indo-European ablaut

In linguistics, the term ablaut designates a system of vowel gradation (i.e. regular vowel variations) in Proto-Indo-European (PIE) and its far-reaching consequences in all of the modern Indo-European languages. (For the general phenomenon, see Apophony.) An example of ablaut in English is the strong verb sing, sang, sung and its related noun song.

The term ablaut (from German ab- in the sense "down, reducing" + Laut "sound") was coined in the early 19th century by the linguist Jacob Grimm, though the phenomenon was first described a century earlier by the Dutch linguist Lambert ten Kate in his book Gemeenschap tussen de Gottische spraeke en de Nederduytsche ("Commonality between the Gothic language and Lower German (Dutch)", 1710).

Preliminary considerations

Vowel gradation is any vowel difference between two related words (e.g. man and woman) or two forms of the same word (e.g. man and men). The difference need not be indicated in the spelling. There are many kinds of vowel gradation in English and other languages, and these are discussed generally in the article apophony. Some involve a variation in vowel length (quantitative gradation: man/woman), others in vowel colouring (qualitative gradation: man/men), and others the complete disappearance of a vowel (reduction to zero: could not → couldn't).

For the study of European languages, one of the most important instances of vowel gradation is the historical Indo-European phenomenon called ablaut, remnants of which can be seen in the English verbs ride, rode, ridden, or fly, flew, flown. For many purposes it is enough to note that these verbs are irregular, but understanding why they are irregular (and indeed why they are actually perfectly regular within their own terms) requires digging back into the grammar of the reconstructed proto-language.

Ablaut is the oldest and most extensive single source of vowel gradation in the Indo-European languages, and must be distinguished clearly from other forms of gradation which developed later, such as Germanic umlaut (man/men, goose/geese, long/length, think/thought) or the results of English word-stress patterns (man/woman, photograph/photography). Confusingly, in some contexts, the terms 'ablaut', 'vowel gradation', 'apophony' and 'vowel alternation' may be used synonymously, especially in synchronic comparisons, but historical linguists prefer to keep 'ablaut' for the specific Indo-European phenomenon, which is the meaning intended by the linguists who first coined the word.

Since ablaut was a regular system in Proto-Indo-European, but survives only as irregular or partially regular variations in the recorded languages, any explanation of the topic has to begin with the prehistoric origins. Proto-Indo-European (PIE) is the hypothetical parent language from which most of the modern and ancient European languages evolved. By comparing the recorded forms from the daughter languages, linguists can infer the forms of the parent language. However, it is not certain how PIE was realised phonetically, and the reconstructions are to be understood as an encoding of the deduced phonemes; there is no correct way to pronounce them. All PIE forms are marked with an asterisk to indicate that they are hypothetical. For more details on these reconstructions, see Proto-Indo-European, Laryngeal theory and Comparative method.

Ablaut in Proto-Indo-European

Proto-Indo-European (PIE) had a regular ablaut sequence that contrasted the five vowel sounds e/ē/o/ō/Ø. This means that in different forms of the same word, or in different but related words, the basic vowel, a short /e/, could be replaced by a long /ē/, a short /o/ or a long /ō/, or it could be omitted (transcribed as Ø).

zero	short	long
Ø	e	ē
	o	ō

When a syllable had a short e, it is said to be in the "e-grade"; when it had no vowel, it is said to be in the "zero grade", etc. Note that when we refer simply to the e-grade or o-grade, the short vowel forms are meant, unless the lengthened grades are specified. The (short) e-grade is sometimes called the full grade.

A classic example of the five grades of ablaut in a single root is provided by the different case forms of two closely related Greek words:

Ablaut grade	PIE (reconstruction)	Greek	(Greek transliterated)	Translation
e-grade or full grade	*ph2-ter-m̥	πα-τέρ-α	pa-ter-a	"father" (noun, accusative)
lengthened e-grade	*ph2-tēr	πα-τήρ	pa-tēr	"father" (noun, nominative)
zero-grade	*ph2-tr-os	πα-τρ-ός	pa-tr-os	"father's" (noun, genitive)
o-grade	*n̥-ph2-tor-m̥	ἀ-πά-τορ-α	a-pa-tor-a	"fatherless" (adjective, accusative)
lengthened o-grade	*n̥-ph2-tōr	ἀ-πά-τωρ	a-pa-tōr	"fatherless" (adjective, nominative)

The syllable in bold is the one being considered. It is crucial also to notice which syllable carries the word stress - that in italics, and in Greek, that with the diacritic. In this atypically neat example, switch to the zero-grade can be seen when the word stress moves to the following syllable, a switch to the o-grade when the word stress moves to the preceding syllable, and a lengthening of the vowel when the syllable is in word-final position. However, as with most PIE reconstructions, scholars differ about the details of this example.

It has often been speculated that the historical development in pre-Indo-European should have been that an original e-grade underwent two changes in some phonetic environments: under certain circumstances it changed its colouring to (long or short) o (the o-grade), and in others it disappeared entirely (the zero-grade). However, since such phonetic conditions that controlled ablaut have never been determined, the position of the word stress may not have been a key factor at all. And since there are many counterexamples like e.g. *deywó- and NPl. *-es that show pretonic and posttonic e-grade, respectively, these rules may never be found anyway. For these reasons, there has recently been made an attempt to analyse Early PIE ablaut in terms of introflexion and root-and-pattern-morphology.^[1] It has been shown that it seems to be highly likely that Early PIE was of the root-inflexional morphological type, as was Proto-Semitic (see also Proto-Indo-European language).

Zero grade

The zero grade of ablaut may appear difficult. In the case of *ph₂trós, which may already in PIE have been pronounced something like /pət-'ros/, it is not difficult to imagine this as a contraction of an older *ph₂terós, pronounced perhaps /pət-er-'os/, as this combination of consonants and vowels would be possible in English too. In other cases, however, the absence of a vowel strikes the speaker of a modern western European language as unpronounceable.

To understand this, one must be aware that PIE had a number of sounds which in principle were consonants, yet could operate in ways analogous to vowels. These are the four syllabic sonorants, the three laryngeals and the two semi-vowels:

• The syllabic sonorants are m, n, r and l, which could be consonants much as they are in English, but could also be held on as continuants and carry a full syllable stress; when this happens, they are transcribed with a small circle beneath them. Compare r and l in some modern Slavic languages, or m and n in some African languages: in Srb, the Serbian word for "Serb", the r carries much the function of a vowel; in the African word Ngazija, the name of a Bantu language, the initial N- should be pronounced with a pulse (nasal plosion), as a full syllable, without the help of a vowel. Modern English dialects have a syllabic consonant /l/ as the final syllable of "bottle" [bɒtl̩ˠ] and a syllabic /m/ in some pronunciations of "enthusiasm".

• The laryngeals could be pronounced as consonants, in which case they were probably variations on the h sound, hence they are normally transcribed as h₁, h₂ and h₃. However they could also carry a syllable stress, in which case they were more like vowels, hence some linguists prefer to transcribe them ə₁, ə₂ and ə₃. The vocalic pronunciation may have originally involved the consonantal sounds with a very slight schwa before and/or after the consonant.

• In pre-vocalic positions, the phonemes u and i were semi-vowels, probably pronounced like English w and y, but they could also become pure vowels when the following ablaut vowel reduced to zero. When u and i came in postvocalic positions, the result was a diphthong. Ablaut is nevertheless regular, and looks like this:

e-grade	o-grade	zero-grade
ei	oi	i
eu	ou	u

Thus any of these could replace the ablaut vowel when it was reduced to the zero-grade: the pattern CVrC (e.g. *bʰergʰ-) could become CrC (*bʰrgʰ-).

However, not every PIE syllable was capable of forming a zero grade; some consonant structures inhibited it in particular cases, or completely. So for example, although the preterite plural of a Germanic strong verb (see below) is derived from the zero grade, classes 4 and 5 have instead vowels representing the lengthened e-grade, as the stems of these verbs could not have sustained a zero grade in this position.

Zero grade is said to be from pre-PIE syncope in unaccented syllables, but in some cases lack of accent does not cause zero grade: *deywó-, nominative plural *-es "god". There does not seem to be a rule governing which unaccented syllables take zero grade and which take stronger grades. Some Indo-Europeanists reject the syncope hypothesis, and instead understand early PIE as a Semitic-type language with discontinuous consonant roots and vowel transfixes.

a-grade

It is still a matter of debate whether PIE had an original a-vowel at all. In later PIE, the disappearance of the laryngeal h₂ could leave an a-colouring and this may explain all occurrences of a in later PIE. However some argue that the e-grade could sometimes be replaced by an a-grade without the influence of a laryngeal. This is controversial, but might help to explain the vowels in class 6 Germanic verbs, for example.

Subsequent development of ablaut

Although PIE only had this one, basically regular ablaut sequence, the development in the daughter languages is frequently far more complicated, and few reflect the original system as neatly as Greek. Various factors such as vowel harmony, assimilation with nasals, or the effect of the presence of laryngeals in the Indo-European (IE) roots and their subsequent loss in most daughter languages, mean that a language may have several different vowels representing a single vowel in the parent language. Thus while ablaut survives in some form in all Indo-European languages, it becomes progressively less systematic over time.

Ablaut explains vowel differences between related words of the same language. For example:

• English fetch and foot both come from the same IE root *ped-, the common idea being "going". The former comes from the e-grade, the latter from the lengthened o-grade.
• German Berg (hill) and Burg (castle) both come from the root *bʰergʰ-, which presumably meant "high". The former comes from the e-grade, the latter from the zero-grade. (Zero-grade followed by r becomes ur in Germanic.)

Ablaut also explains vowel differences between cognates in different languages.

• English tooth comes from Germanic *tanþ-uz, which is related to Latin dens, dentis and Greek ὀδούς, ὀδόντος (same meaning), reflected in the English words dentist and orthodontic. The reconstructed IE root is identical to the Latin: *dent-. The consonant differences can be explained by regular sound shifts in primitive Germanic, but not the vowel differences: by the regular laws of sound changes, Germanic a goes back to PIE o. The explanation is that the Germanic and Greek words developed from the o-grade, the Latin word from the e-grade. (Going a step further back, some scholars reconstruct *h₁dónts, from the zero grade of the root *h₁ed- 'to eat' and the participal -ont-, so explaining it as 'the eating one')
• English foot, as mentioned above, comes from the lengthened o-grade of *ped-. Greek πούς, ποδός and Latin pes, pedis (cf. English octopus and pedestrian), come from the (short) o-grade and the e-grade respectively.

For the English-speaking non-specialist, a good reference work for quick information on IE roots, including the difference of ablaut grade behind related lexemes, is Calvert Watkins, The American Heritage Dictionary of Indo-European Roots, 2nd edition, Boston & New York 2000.

(Note that in discussions of lexis, IE roots are normally cited in the e-grade and without any inflections.)

Ablaut and grammatical function

In PIE, there were already ablaut differences within the paradigms of verbs and nouns. These were not the main markers of grammatical form, since the inflection system served this purpose, but they must have been significant secondary markers.

An example of ablaut in the paradigm of the noun in PIE can be found in *pértus, from which the English words ford and (via Latin) port are derived.

		root (p-r)	suffix (t-u)
Nominative	*per-tu-s	e-grade	zero-grade
Accusative	*per-tu-m	e-grade	zero-grade
Genitive	*pr̥-teu-s	zero-grade	e-grade
Dative	*pr̥-teu-ei	zero-grade	e-grade

An example in a verb: *bʰeidʰonom "to wait" (cf. "bide").

Infinitive	*bʰeidʰ-ono-m	e-grade
Perfect (3rd singular)	*bʰe-bʰoidʰ-e	o-grade	(note reduplicating prefix)
Perfect (3rd plural)	*bʰe-bʰidʰ-nt	zero-grade	(note reduplicating prefix)

In the daughter languages, these came to be important markers of grammatical distinctions. The vowel change in the Germanic strong verb, for example, is the direct descendant of that seen in the Indo-European verb paradigm. Examples in modern English are:

Infinitive	Preterite	Past participle
sing	sang	sung
give	gave	given
strive	strove	striven
break	broke	broken

It was in this context of Germanic verbs that ablaut was first described, and this is still what most people primarily associate with the phenomenon. A fuller description of ablaut operating in English, German and Dutch verbs and of the historical factors governing these can be found at the article Germanic strong verb.

The same phenomenon is displayed in the verb tables of Latin, Ancient Greek and Sanskrit. Examples of ablaut as a grammatical marker in Latin are the vowel changes in the perfect stem of verbs.

Present tense	Perfect
ago	egi	"to do"
video	vīdi	"to see"	(vowel lengthening)
sedeo	sēdi	"to sit"	(vowel lengthening)
cado	cecidi	"to fall"	(note reduplicating prefix)

Ablaut can often explain apparently random irregularities. For example, the verb "to be" in Latin has the forms est (he is) and sunt (they are). The equivalent forms in German are very similar: ist and sind. The same forms are present in Slavic languages – est and sut' . The difference between singular and plural in this languages is easily explained: the late PIE root is *es- (going back to an earlier h₁es- with subsequent loss of the laryngeal). In the singular, the stem is stressed, so it remains in the e-grade, and it takes the inflection -t. In the plural, however, the inflection -nt was stressed, causing the stem to reduce to the zero grade: *es-n̥t → *s-n̥t. When, much later, the daughter languages became uncomfortable with this nasal plosion, they introduced compensatory vowels after the /s/. See main article: Indo-European copula.

Some of the morphological functions of the various grades are as follows:

e-grade:

• Present tense of thematic verbs; root stress.
• Present singular of athematic verbs; root stress.
• Accusative and vocative singular, nominative/accusative/vocative dual, nominative plural of nouns.

o-grade:

• Verbal nouns with ending stress.
• Present tense of causative verbs; stem (not root) stress.
• Perfect singular tense.

zero-grade:

• Present dual and plural tense of athematic verbs; ending stress.
• Perfect dual and plural tense; ending stress.
• Past participles; ending stress.
• Some verbs in the aorist (the Greek thematic "second aorist").
• Oblique singular/dual/plural, accusative plural of nouns.

lengthened grade:

• Nominative singular of many nouns.

See also

• Augment
• Apophony
• Germanic Umlaut
• Guna (in grammar)
• I-mutation
• Inflected language
• Reduplication
• Vriddhi

References

• Beekes, Robert S. P. (1995). Comparative Indo-European Linguistics: An Introduction. Amsterdam: John Benjamins. ISBN 90-272-2150-2 (Europe), ISBN 1-55619-504-4 (U.S.). 
• Coetsem, Frans van (1993). Ablaut and Reduplication in the Germanic Verb (=Indogermanische Bibliothek. vol 3). Heidelberg: Winter Verlag. ISBN 3-8253-4267-0. 
• Kuryłowicz, Jerzy; Manfred Mayrhofer (1968/9). Indogermanische Grammatik. Heidelberg: Winter Verlag. ISBN 3-533-03487-9. 
• Meier-Brügger, Michael (2002). Indogermanische Sprachwissenschaft. de Gruyter. ISBN 3-11-017243-7. 
• Szemerenyi, Oswald J. L.. Introduction to Indo-European Linguistics. Clarendon: Oxford University Press. ISBN 0-19-824015-5. 
• Watkins, Calvert (2000). The American Heritage Dictionary of Indo-European Roots (2nd edition ed.). Boston & New York: Houghton Mifflin. ISBN 0-618-08250-6.