In English, t is seldom, if ever, silent or powerless.  In depot, however, a word borrowed from the French, we do not sound it; and in chestnut, which is a compound of our own, it is much oftener written than heard.  In often and soften, some think it silent; but it seems rather to take here the sound of f.  In chasten, hasten, fasten, castle, nestle, whistle, apostle, epistle, bustle, and similar words, with their sundry derivatives, the t is said by some to be mute; but here it seems to take the sound of s; for, according to the best authorities, this sound is beard twice in such words. Th, written in Greek by the character called Theta, ([Greek:  th] or O capital, [Greek:  th] or [Greek:  th] small,) represents an elementary sound; or, rather, two distinct elementary sounds, for which the Anglo-Saxons had different characters, supposed by Dr. Bosworth to have been applied with accurate discrimination of “the hard or sharp sound of th,” from “the soft or flat sound.”—­(See Bosworth’s Compendious Anglo-Saxon Dictionary, p. 268.) The English th is either sharp, as in thing, ethical, thinketh; or flat, as in this, whither, thither.

“Th initial is sharp; as in thought:  except in than, that, the, thee, their, them, then, thence, there, these, they, thine, this, thither, those, thou, thus, thy, and their compounds.”—­W.  Allen’s Grammar, p. 22.

Th final is also sharp; as in south:  except in beneath, booth, with, and several verbs formerly with th last, but now frequently (and more properly) written with final e; as loathe, mouthe, seethe, soothe, smoothe, clothe, wreathe, bequeathe, unclothe.

Th medial is sharp, too, when preceded or followed by a consonant; as in Arthur, ethnic, swarthy, athwart:  except in brethren, burthen, farther, farthing, murther, northern, worthy.  But “th between two vowels, is generally flat in words purely English; as in gather, neither, whither:  and sharp in words from the learned languages; as in atheist, ether, method”—­See W.  Allen’s Gram., p. 22.

“Th, in Thames, Thomas, thyme, asthma, phthisis, and their compounds, is pronounced like t.”—­Ib.

XXI.  OF THE LETTER U.

The vowel U has three sounds which may be considered to be properly its own:—­

1.  The open, long, full, primal, or diphthongal u; as in tube, cubic, juvenile.

2.  The close, curt, short, or stopped u; as in tub, butter, justice, unhung.

3.  The middle u, resembling a short or quick oo; as in pull, pulpit, artful.

U forming a syllable by itself or U as naming itself is nearly equivalent in sound to you, and requires the article a, and not an, before it; as, a U, a union.