Well, they're a little separate -- the umlaut processes are in some cases not recoverable. From Bender 1968:
(It's an interesting paper -- in the introduction, he suggests that other Micronesian languages, specifically Kosraean and Chuukic, might have VVSs as well.)Thus one can say concerning forms such as these that é is either a lowered i (when the stem vowel e is dropped from independent, unsuffixed forms) or a raised e (when the stem vowel i is dropped), but its double origin makes biuniqueness impossible; one could not know whether to transcribe [bʷʊŋʷ] (béŋʷ) 'night' as beŋʷi or biŋʷe (with all word-final vowels to be dropped by a general reading rule) without additional information -- the quality of its stem vowel when suffixed. To complicate matters further, some forms have undergone reanalysis: one can hear both beŋʷin yinney and biŋʷen yinney 'night of yesterday' 'night before last' (but always béŋʷ 'night'). There is every indication that all instances of é can be derived ultimately from i or e and so written in base forms, but for reasons of the sort just noted, I have retained the fourth vowel ... while recognizing that the underlying Marshallese system is a three-vowel system.
"{yiy} is for a "dwelling upon" version of i that occurs at the beginning of certain words, now generally written ii in the "new" orthography, phonetically pronounced [iː] and existing on the phonemic level as /jijj/, effectively making it identical to {yiyy}."I’m not sure I understand this. Where do you see /yiyy/? And where did you see that /yiyiy/ is prohibited?
I don't see any instances of word-initial /yiyiy/.
It's written <ii>.I don’t understand this either. What do you mean by ‘orthographic long i’?