A vowel is a letter that can be perfectly sounded by itself. The vowels are a, e, i, o, u, and sometimes w and y. W and y are consonants when they begin a word or syllable; but in every other situation they are vowels.
A consonant is a letter that cannot be perfectly sounded without the help of a vowel; as, b, d, f, l. All letters except the vowels are consonants.
Consonants are divided into mutes and semi-vowels.
The mutes cannot be sounded at all without the aid of a vowel. They are b, p, t, d, k, and c and g hard.
The semi-vowels have an imperfect sound of themselves. They are f, l, m, n, r, v, s, z, x, and c and g soft.
Four of the semi-vowels, namely, l, m, n, r, are called liquids, because they readily unite with other consonants, and flow, as it were, into their sounds.
A diphthong is the union of two vowels, pronounced by a single impulse of the voice; as oi in voice, ou in sound.
A triphthong is the union of three vowels pronounced in like manner; as, eau in beau, iew in view.
A proper diphthong has both the vowels sounded; as, ou in ounce. An improper diphthong has only one of the vowels sounded; as, oa in boat.
II. SYLLABLES. A Syllable is a distinct sound, uttered by a single impulse of the voice; as, a, an, ant.