PIE e/o Ablaut

[petegray]

>> .. pra-ugam

> To what IE root do you propose to attribute [-ugam]?

Hyeug - to yoke.   Either the /y/ or the /H/ has caused hiatus here by
dropping out.   This means that your "rule" for the combination /a + u/ is
not always true.

>su-astaye.

The problem is again that your "rule" of consonant/vowel allophones doesn't
work and would need revising to cover cases like this.   Perhaps you can
revise it without trouble - but in its present form, a succession of two
vowels is not possible.

Peter