TRIPHTHONGS BEGINNING WITH E.
Eau, a French triphthong, sounds like open o; as in beau, flambeau, portmanteau, bureau: except in beauty, and its compounds, in which it is pronounced like open u, as if the word were written buty.
Eou is a combination of vowels sometimes heard in one syllable, especially after c or g; as in crus-ta-ceous, gor-geous. Walker, in his Rhyming Dictionary, gives one hundred and twenty words ending in eous, in all of which he separates these vowels; as in ex-tra-ne-ous. And why, in his Pronouncing Dictionary, he gave us several such anomalies as fa-ba-ce-ous in four syllables and her-ba-ceous in three, it is not easy to tell. The best rule is this: after c or g, unite these vowels; after the other consonants, separate them.
Ewe is a triphthong having the sound of yu, and forming a word. The vulgar pronunciation yoe should be carefully avoided.
Eye is an improper triphthong which also forms a word, and is pronounced like open i, or the pronoun I.