How did a rough breathing develop before all words starting with an upsilon in Ancient Greek? This is a commonly noted fact about the distribution of these sounds (or rather spellings), but I’m having a hard time figuring out the etymological reason for it.

In some words, it is easily explicable as the regular outcome of a word-initial *s- in Proto-Indo-European: *súpnos > ὕπνος (húpnos)

But in other words, there is no *s reconstructed for the PIE form. Are there any historical linguistics hypotheses about the source of the rough breathing in these words (e.g. a prothetic *s- prefix that later weakened to a rough breathing, a shift [w] > [v] > [f] > [h], a sound change inserting /h/ before all word-inital /u/ at some point in Ancient Greek (that seems phonetically unmotivated to me, although I guess it's the most straightforward option), something like that).

Some example words (I’m taking these from Wiktionary):

  • *wódr̥ > ὕδωρ (húdōr)
  • *webʰ- > ὑφαίνω (huphaínō)
  • *upo > ὑπό (hupó),
  • *uperi > ὑπέρ (hypér)

Are these last two related to the prothetic s- seen in Latin sub, super? (Wiktionary gives super < *eks-uper, but ὑπέρ < *uperi, which would seem to suggest that it is just a coincidence).

A related question: a rough breathing seems to also have developed in some words that didn't start with upsilon, but that had *w in their PIE form. In most words starting with *w in PIE, like *wérǵom > ἔργον (érgon) the *w simply developed to ϝ (representing the sound /w/) and was later lost, leaving a smooth breathing behind. Why did a rough breathing develop in the following words?

  • *wek(ʷ)speros > ἕσπερος (hésperos)
  • *wes- > ἕννυμι (hénnumi)

Is this related to the *s that comes later in each of these roots?

I don't know if it's also relevant that the PIE word-initial cluster *wr- merged with the reflex of the cluster *sr- in Greek, giving ῥ (rh, rho with a rough breathing).


Greek initial /h/ develops regularly from IE *s and non-syllabic *i. But (as you mention) initial υ always has rough breathing, even where it was not preceded by etymological /s/ or /j/. One explanation that has been considered is that Greek initial /u/ developed a /j/ on-glide, very much as has happened in English (unit, use, united…), which then partook in the development of inherited /j/ to /h/.

  • Thanks, that's helpful! Would you mind also adding in what conditions PIE *y- developed to Greek /h/? This Wikipedia article says that completely word-initial *y was strengthened to dz (ultimately resulting in a reflex of ζ) but the wording there seems to indicate that this didn't occur after a laryngeal. So is the relevant sound change actually PIE *Hy- > Greek /h/ ? en.wikipedia.org/wiki/Proto-Greek_language – brass tacks Apr 22 '15 at 0:18
  • 2
    I don't think it's the case that English u developed an on-glide. Modern English "long u" doesn't come from Middle English /u/ at all, but is a merger of the borrowed French /y/ with several ME diphthongs. It seems unlikely that anything similar could have happened in Greek. – TKR Apr 22 '15 at 1:22

As a conjecture, it seems possible that the generalized rough breathing before #u- has to do with the cross-linguistic tendency for high vowels to produce extra turbulence, which can then be phonologized. Most often this takes the form of spirantization or affrication of stops before high vowels, but aspiration can also result: in Ikalanga (Bantu), stops become aspirated before /i u/. I don't know of an exact parallel to the Greek case, though.

For your second question about the w- > h- change, this is indeed often said to be somehow due to the following -s- in most of these words. This isn't unproblematic, though, since (a) the phonetic justification for such a change seems slim, and (b) there are counterexamples of both kinds: ἑκών, ἕδνα with unexpected rough breathing, ἄστυ with no rough breathing where this account would predict it.

  • But why does it happen before /u/ but not before /i/? – fdb Apr 22 '15 at 8:22
  • Maybe something to do with their relative phonetics, e.g. /i/ was not as high as /u/? I'm just speculating here, of course. – TKR Apr 22 '15 at 18:01

It is known that in PIE any words starting with r- were prohibited. It is conjectured that this was the case of all sonorants.

For instance, the pronouns usually rendered with initial i̯- has been recently reconstructed with an initial laryngeal e̯i̯-.

One of your roots, the u̯ebh- (wasp, web, weave etc) is known to start with a laryngeal, though what laryngeal it was is different in Mallory&Adams and Brill Latin.

  • So if I understand correctly, you're suggesting that the laryngeal is reflected as a rough breathing? Does this happen anywhere else? – brass tacks Apr 21 '15 at 21:00
  • @sumelic in this root, definitely there was a laryngeal. Wherther the rough breathing arose from it or after the laryngeal disappeared is another question (Greek is known to be conservative with respect of laryngeals). – Anixx Apr 21 '15 at 21:02
  • 2
    OK, but I thought laryngeals are usually reflected by vowel-coloring rather than breathing in Greek. So, I don't see how the rough breathing is explained by the historical presence of a laryngeal consonant. – brass tacks Apr 21 '15 at 21:05
  • 3
    I don't understand. This seems like a non sequitur, when my original question was not about laryngeals, but about the rough breathing... If you can't explain a connection, how is this answer on topic? – brass tacks Apr 21 '15 at 21:08
  • 1
    I think it's generally agreed that PIE words could start with i̯-. At least, the most common explanation for the "double reflex" of PIE i̯- in Greek is that i̯- gave zeta while Hi̯- gave y-. – TKR Apr 22 '15 at 1:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.