Here, Stevens seems to be saying that the original pronunciation of Tummeor was [te'mi:] or [te'mi:e], with the centring diphthongal
glide represented by the final -r in his written form.
Vowel nuclei in RP English have alternately been described as short monophthongal vs long monophthongal vs diphthongal
Concretely, the author addresses the phonemes /e/ and /o/ as more or less diphthongal
A note on DRESS comments on its 'upgliding', diphthongal
realisation before /d/ and /n/ (generally dental in Shetland).
forms, first recorded, according to him, in the Ancrene Riwle, were rare in other 13th century texts.
And Tosca sings L'ardente amante mia, with the diphthongal
adjective set to two dotted quarter notes.
This, in turn, is counterpoised by the sudden diphthongal
echo of "mine" in "thine.
For GOOSE, which has both monophthongal and diphthongal
variants, we find that the younger speaker's pronunciations are much more fronted than the older speaker's, overlapping with FLEECE to some extent.
The original (lost) Visigothic language may have had both diphthongal
and monophthongal sounds in opposition to each other in the relevant lexemes, but we do not know how they were spelt in Visigothic manuscripts.
New Yawk Tawk also features a diphthongal
/aw/ sound that in heavy Nooyawkese sounds almost disyllabic.
1988b "'Historische Grammatik and Middle English diphthongal
systems", in: Dieter Kastovsky - Gero Bauer (eds.
The old diphthongs are a salient dialect feature that is characteristic of dialects spoken in remote parts of the Swedish language area, and diphthongal
realizations (or secondary diphthongs) of the long vowel phonemes are, in Finland, confined to the dialects of a small area north and south of Kristinestad.