From: G&P
Message: 61578
Date: 2008-11-13
>how do we establish the existence of H1 and H2
>if at the same time, we admit a purely vocalic a/a: and e/e: ablaut ?…> All this being wrong, I'm afraid.
It’s still an interesting question, to see how far we could establish any, or two or three laryngeals without using vowel colouring. I agree with you (of course) that vowel colouring is the main evidence for distinguishing them. I’d go further, and ask if we could establish them without Greek. But the question feels like the sort of thing one should know an answer to.
Peter