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_.

A word of one syllable, is termed a Monosyllable; a word of two
syllables, a Dissyllable; a word of three syllables, a Trisyllable; a
word of four or more syllables, a Polysyllable.

III. WORDS. Words are articulate sounds, used by common consent, as
signs of our ideas.

Words are of two sorts, primitive and derivative.

A _primitive_ word is that which cannot be reduced to a simpler word in
the language; as, _man, good_.