What were the phonetic values of the Proto-Indo-European (PIE) “laryngeals”? The natural first place to look is in the Anatolian languages, because they are the only Indo-European languages that preserve direct reflexes of the laryngeals. According to Melchert (1994), Proto-Anatolian (PA) had two laryngeals, *H and *h. *H was the regular reflex of PIE *h₂, while *h was a reflex of both *h₃, in word-initial position, and *h₂, in the positions where it was affected by Anatolian lenition (more on this below). PIE *h₁, and *h₃ outside of word-initial position, were elided everywhere in PA, as in the other Indo-European languages.
There is disagreement over the outcome of *h₃ in word-initial position; some other authors propose that it was lost in that position too, just like *h₁. The problem is that in all of the non-Anatolian Indo-European languages, PIE *h₁o, *h₂o and *h₃e have identical outcomes. Hence there are cognate sets like Hittite arta and Greek ō̂rto ‘stands’, for which the pro-word-initial-*h₃-loss advocates reconstruct PIE *h₃érto and the anti-word-initial-*h₃-loss advocates reconstruct PIE *h₁órto, and cognate sets like Hittite ḫawis and Latin ovis ‘sheep’, for which the pro-word-initial-*h₃-loss advocates reconstruct PIE *h₂ówis and the anti-word-initial-*h₃-loss advocates reconstruct PIE *h₃éwis. Hence, to find out what happened we need to look at examples where *h₃ is in word-initial position before a consonant. But such examples are few in number. Melchert (1987) gives the following two examples:
- PIE *h₃reǵ > Hittite ḫarganāu- ‘palm, sole’ (with a *-nṓw suffix), Greek orégō ‘I stretch out [esp. hands or feet]’ (with an *-oh₂ suffix).
- PIE *h₃pus- > Hittite ḫapuš- ‘shaft of an arrow, stalk of a reed, penis’, Greek opuíō ‘marry’ (with a *-yoh₂ suffix).
Both examples are to some extent semantically problematic, especially the second one. In fact, Kloekhorst (2005), in an entire paper on the Hittite word ḫapuš-, argues that its actual stem is ḫāpūšašš- and that its meaning when it refers to a body part is ‘shin’, not ‘penis’ (the word only appears in a text describing a ritual where a dead ram’s body parts are placed on the corresponding body parts of a sick person in order to heal them, and its meaning is deduced based on the assumption that the body parts are arranged in a logical order). I therefore find the second example unconvincing. The first example still stands, and I would accept that *h₃ is retained in word-initial position on that basis, but the conclusion is obviously very tentative.
I mentioned Anatolian lenition above. An explanation of this change will be helpful. PA had two series of stops, which I will refer to as the fortis series and lenis series. The term “fortis” just means “strong” and the term “lenis” just means “weak”; I use these terms because there is disagreement over what the nature of the contrast between these two series was (I have an opinion on what it was, but it’s not particularly relevant for this post). In general, the PIE voiceless stops became fortis stops in PA, while the PIE voiced stops and voiced aspirated stops became lenis stops in PA. However, the change known as Anatolian lenition resulted in the PIE voiceless stops becoming lenis stops in certain positions, namely: word-finally, after accented long vowels, after accented diphthongs (i.e. accented vowel + *y or *w sequences) and between unaccented vowels.
The interesting thing about Anatolian lenition is that in the exact same set of environments, PIE *h₂ was reflected as *h rather than *H. So Anatolian lenition seems to have applied to *h₂ as well as the voiceless stops. The conclusion we can draw from this is that the contrast between PA *H and PA *h was of the same nature as the contrast between the PA fortis stops and the PA lenis stops. That is, *H was fortis and *h was lenis. Since *H is the regular outcome of PIE *h₂, this indicates that PIE *h₂ was voiceless. If it was a voiced consonant, it would probably have behaved like the PIE voiced stops, rather than the PIE voiceless stops, so it would have been unaffected by Anatolian lenition.
If PIE *h₃ was preserved in word-initial position as PA *h, it is tempting to identify *h with *h₃ and say that we can also conclude that *h₃ was voiced. But things are not so straightforward with *h₃, as there is no direct evidence that the outcome of word-initial PIE *h₃ and the outcome of PIE *h₂ when affected by Anatolian lenition were ever the same phoneme. In the Anatolian languages that were written in a cuneiform syllabary (Hittite, Palaic and Luwian), the outcomes of word-initial PA *H and *h were both indicated by the same syllabograms in writing; these outcomes in this position are conventionally transcribed ḫ. In word-medial position, the two outcomes are distinguished: the outcome of PA *h is written the same way it is in word-initial position, but the outcome of PA *H is written with syllabograms indicating ḫ at the end of the syllable before syllabograms indicating ḫ at the start of the syllable. In other words, the outcome of PA *H is written as a double consonant. Naturally, it was impossible to indicate the difference between *h and *H in the same way in word-initial position, so even if *h and *H were distinguished in word-initial position we should not expect the distinction to be made in the script. By the way, the stops are written in the exact same way, as single consonants (when lenis) or double consonants (when fortis), but always as single consonants in word-initial position. Anyway, the point is, it is entirely possible that PIE *h₃ became PA *H in word-initial position, without at any point being identified with *h, if you go by the evidence from the cuneiform languages alone.
So, the idea that PIE *h₃ became *h, specifically, rather than *H or something else entirely in word-initial position is based on evidence from the much more sparsely-attested Late Anatolian languages: Lydian, Carian, Lycian, Sidetic and Pisidian. In Lydian, the little evidence we have suggests that the PA laryngeals were both elided in all positions, so this language is of no help. Melchert’s basis for supposing that PIE *h₃ became *h is Lycian. In Lycian, it appears that PA *h was lost in word-initial position (c.f. Lycian epirije- ‘sell’ = Hittite ḫappariya- ‘deliver’ < PIE *h₃ep- ‘work’ [with a suffix], c.f. Latin ops ‘ability to help’ [with a *-s suffix]), but PA *H was retained and written with the Greek letter chi, transcribed as x (c.f. Lycian xñtawati = cuneiform Luwian ḫandawati < PIE *h₂ent- ‘front’ [with a suffix], c.f. English end). If this is correct, it does suggest that the outcome of word-initial *h₃ was “weaker” than the outcome of word-initial *h₂. Having established that the evidence isn’t overwhelmingly convicing, I would nevertheless tentatively assume that *h₃ was voiced in PIE based on the Anatolian evidence.
Now that we have some idea about the nature of the contrast between *h₂ and *h₃, what can we say about their actual realisations? The best evidence we have is the use of the ḫ-containing syllabograms for indicating laryngeals in Hittite. In Akkadian, ḫ continues Proto-Semitic (PS) *ḫ, which corresponds to Arabic ḫ /χ/ and Hebrew ḥ /ħ/. There is also a PS phoneme *ḥ which corresponds to ḥ /ħ/ in both Arabic and Hebrew, while being elided in Akkadian; hence, it seems that PS *ḫ should be reconstructed as /χ/ and PS *ḥ should be reconstructed as /ħ/. The simplest hypothesis on the Akkadian pronunciation of is ḫ is that it is unchanged from Proto-Semitic and hence pronounced as /χ/ (or perhaps some other voiceless dorsal fricative).
Lycian also preserves direct outcomes of the laryngeals, but unfortunately it is hard to interpret the Lycian orthography. Lycian is written using an alphabet adapted from the early Greek alphabet. The outcome of PA *H appears in Lycian as three different phonemes, according to Melchert. One of them is written with a letter corresponding to Greek chi or psi (these two letters were graphic variants of each other in early Greek). This one is transcribed x. Another is written with a letter of unknown origin (at least to me; it doesn’t look like any Greek letter I know of). This one is transcribed q. (There is a Lycian block in Unicode but virtually no fonts support it, so I’ve included a picture of q below.) The other is written with a letter corresponding to Greek kappa, and is transcribed k. The conditioning of the split between these three phonemes is quite unclear, but Melchert proposes that PA *H becomes k between front vowels, q between word boundaries, consonants or back vowels and front vowels and x elsewhere. If this is the case, the three consonants can probably be arranged in the order k, q, x, from most palatalised to least palatalised. What the manner of articulation of these consonants was is a puzzle. In Greek, kappa represents a voiceless unaspirated stop /k/, while chi represents a voiceless aspirated stop /kʰ/; chi would be the natural choice to represent /x/ if it was a phoneme in Lycian. But in Lycian the two letters contrast in palatalisation, rather than aspiration. I think there are too many uncertainties with regards to Lycian for it to allow us to conclude anything.
So, my best guess for the values of the laryngeals in PIE based on the Anatolian evidence alone is that *h₂ and *h₃ were voiceless and voiced uvular fricatives, respectively (they might have been velar rather than uvular). Since *h₁ was elided in Anatolian, we do not have any direct evidence for what its realisation was, but we can deduce that it was probably “weaker” than *h₂ and *h₃. This would suggest that it was a true laryngeal: either /ʔ/ or /h/.
What about the evidence from outside of Anatolian? It turns out that this evidence is difficult to reconcile with the Anatolian evidence. In all of the Indo-European languages, we see the effects of a rule known as laryngeal colouring, by which short PIE *e becomes *a adjacent to *h₂ and short PIE *e becomes *o adjacent to *h₃. The rule applies in Anatolian too, so it was probably already in effect in PIE; roots like *h₃er- ‘eagle’ should really be transribed *h₃or- (but transcribing them with *e makes it easier to describe PIE morphology). Now, there is no reason why voiceless and voiced variants phonemes with the same place and mannner of articulation should cause adjacent to *e to turn into different vowels. If *h₂ and *h₃ were really counterparts of each other differing only in voicing, we would expect *e either to become *a adjacent to either or to become *o adjacent to either.
It’s tempting to suppose that *h₃ was labialised, to account for the colouring of adjacent *e to *o. But in PIE, labialised and non-labialised velars did not contrast adjacent to *w and *u: adding the suffix *-us to the root *h₁lengʷʰ- ‘light [in weight]’ yields *h₁léngʰus (c.f. Greek elakhús ‘little’). Therefore, if *h₃ was the labialised counterpart of *h₂ we would expect to see the same neutralisation of the contrast in this environment. As far as I can tell, this neutralisation does not occur: we have PIE *gwih₃wós ‘alive’ (c.f. Latin vīvus, English quick), which definitely has *h₃, because it is related to PIE *gʷíh₃woh₂ ‘I live’ > *gʷyṓwō (not *gʷyā́wō) > Greek zṓō ‘I live’, but also *h₂wéh₁mi ‘I blow’ > *áwēmi (not *ówēmi) > Greek áēmi ‘I blow’. The contrast would not have been neutralised if *h₂ and *h₃ differed in voicing as well as labialisation, but that would be a weird combination of contrasts, and until I see a language that uses the same combination I wouldn’t consider it a possibility.
There is more that could be said about the evidence from outside of Anatolian, but this post has got long enough already. I might post more about this later, but for now all I can say about the phonetic values of the laryngeals is that they are still a mystery, although hopefully you now have some understanding of why they are such a mystery 🙂