Hi everyone,

I'm trying to establish the order in which the aforementioned
phonological evolutions occurred. I think the meaning of "i-mutation"
and "u-mutation" is pretty clear ; by "vowel dropping", I mean the
loss of the vowel in the last unstressed syllable of some stems ending
with a single 'l' or 'n' when the ending begins with a vowel.

Example with "ketill", n.pl: *katilar > katlar

"Ketill" looks to me like an interesting starting point to my
investigations since it exhibits the three phenomena. First I should
explain my understanding of the way they affected this word:

- I believe the original stem is "katil"
- Everywhere vowel dropping did not occur, the root "a" changed into
"e" by i-mutation. Why the dat. sg. "katl-i" didn't change into
"ketl-i" is unclear to me (perhaps did the earlier
proto-germanic/proto-norse ending become an "i" when i-mutation had
ceased being productive ?)
- The dat.pl "kǫtlum" is due to u-mutation, as usual.

Now, here are the conclusions I draw from these observations:

- Vowel dropping necessarily occurred before u-mutation ; else in
dat.pl, the stem vowel 'a' wouldn't have directly preceded the 'u' of
the ending.
- It also occurred before i-mutation, or the 'a' would have turned
into an 'e' everywhere (and there would have been no u-mutation in
dat.pl.)

But I fail to establish in which order i-mutation and u-mutation
happened. I know u-mutation still was productive in Old
Norse/Icelandic whereas i-mutation wasn't ; but i-mutation could have
been a very short phenomenon that started after and ended before
u-mutation.

So my questions are the following:
- Do you support my "reading" of this word ?
- Do you have insights, comments, facts, links, etc. regarding this
question ?

Thank you for reading this !

Gaƫl