What about those semivowels, anyway?

Should we finally make the decision to add /w/ and /y/ to the phonology? There would need to be certain distribution restrictions, in short:

• /y/ cannot occur before /i/ or after /i/ or /e/ due to the serious danger of confusion between e.g. ia/iya, ea/eya, and the fact that [ji] is difficult to pronounce and tends to be unstable cross-linguistically.

• In parallel fashion, /w/ cannot occur before /u/ or after /u/ or /o/ due to the danger of confusion between e.g. ua/uwa, oa/owa, and the fact that [wu] is difficult to pronounce and tends to be unstable.

For these reasons, /w/ and /y/ probably can't be used in the derivational system: we'd ideally like to be able to apply every suffix to every root, but -wa, for example, could not be added to any root ending in -o or -u -- the distinction between pokoa/pokowa or pukua/pukuwa really can't bear functional load.

Come to think of it, what about the muya/moya or tiwa/tewa kind of distinction? This seems harder, at least for English speakers, than anything else in the phonology. And, and, and, can we have both ona and wona, ena and yena? See, this is exactly why this thought process stalled out last time.

Okay, putting the above panic attack out of our thoughts for a moment, what would these putative roots look like, anyway? Here are 50 from Randword:

weu
niwo
piwe
niwa
yolu
kewi
yuka
lawa
hiwe
hewo
hewi
kaye
hewa
siwi
puyo
siwa
wali
lewo
yoya
toya
yona
hayu
woo
poyu
noyo
newi
tewi
wawo
yeso
kiwe
hawa
naya
oyu
sewa
yuyo
toyu
siwo
mewa
lewe
kawo
womu
payu
koyu
siwe
yumi
iwe
wole
mewe
taye
kiwa

Hm. I like some of these very much, others not at all. This is a really hard decision to make. I have a conservative streak with Koa that's probably at least partially responsible for my continuing to like this language after all these years, and it's sort of urging me not to do any rash phoneme-adding at this point.

The bottom line is that the above words don't feel like Koa to me, they feel more like Yorùbá or something. There's nothing wrong with this in itself, of course, but I don't think it's the direction I want to go in right now with this language. So there it is.