Ou has the sound of oo.
Ex. clou, nail; sou, cent; outil, tool; boule, bowl.
Eu has a sound resembling that of u in spur, but it is always long.
Ex. peu, little; seul, alone; meunier, miller.
It has the sound of u (e being silent) in certain forms of the verb avoir.
Ex. eu, had; j'eus, I had; que j'eusse, that I might have.
The same is the case in à jeun, fasting.
Œu has the same sound as eu.
Ex. œuf, egg; vœu, vow.
Oi, has the sound of French oua.
Ex. moi, me; roi, king; gloire, glory; oie, goose.
Oi before n is sounded as if it were spelt ouin.
Ex. foin, hay; loin, far; soin, care.
Oi is somewhat like o (i being silent) in oignon, onion; encoignure, corner angle; poignard, poniard; poignée, handful, and a few others.
If these combinations of vowels have a circumflex accent over the second vowel, the sound is lengthened considerably.
Ex. maître, master; voûte, vault; croître, to grow.
If it is desirable, for etymological purposes, to preserve the original sound of each vowel separately, a diaeresis (..) is placed over the second vowel.
Ex. Saül, Saul; naïf, artless; Moïse, Moses; baïonnette, bayonet.
The same effect is produced when the first vowel of ei and eu is accented.
Ex. obéir, to obey; réussir, to succeed.
N. B.—Oi was formerly used in many nouns, and always in the imperfect and conditional tenses of verbs, instead of the modern form ai, introduced by Voltaire. It had the same sound as ai, which requires attention, as many works still retain the former spelling.
b. All other combinations of vowels produce diphthongs, forming either one or two syllables.
If e should be the first of two such vowels and unaccented, it is silent.
Ex. Jean, John; flageolet, flageolet; geôlier, jailer.
