Words ending with any double letter, preserve it double in all derivatives formed from them by means of prefixes: as, see, foresee; feoff, enfeoff; pass, repass; press, depress; miss, amiss; call, recall; stall, forestall; thrall, inthrall; spell, misspell; tell, foretell; sell, undersell; add, superadd; snuff, besnuff; swell, overswell.
OBSERVATION.—The words enroll, unroll, miscall, befall, befell, bethrall, reinstall, disinthrall, fulfill, and twibill, are very commonly written with one l, and made exceptions to this rule; but those authors are in the right who retain the double letter.
RULE VIII.—FINAL LL.
Final ll is peculiar to monosyllables and their compounds, with the few derivatives formed from such roots by prefixes; consequently, all other words that end in l, must be terminated with a single l: as, cabal, logical, appal, excel, rebel, refel, dispel, extol, control, mogul, jackal, rascal, damsel, handsel, tinsel, tendril, tranquil, gambol, consul.
OBSERVATION.—The words annul, until, distil, extil, and instil, are also properly spelled with one l; for the monosyllables null, till, and still are not really their roots, but rather derivatives, or contractions of later growth. Webster, however, prefers distill, extill, and instill with ll; and some have been disposed to add the other two.
RULE IX.—FINAL E.
The final e of a primitive word, when this letter is mute or obscure, is generally omitted before an additional termination beginning with a vowel: as, remove, removal; rate, ratable; force, forcible; true, truism; rave, raving; sue, suing; eye, eying; idle, idling; centre, centring.
EXCEPTIONS.—1. Words ending in ce or ge, retain the e before able or ous, to preserve the soft sounds of c and g: as, trace, traceable; change, changeable; outrage, outrageous. 2. So, from shoe, we write shoeing, to preserve the sound of the root; from hoe, hoeing, by apparent analogy; and, from singe, singeing; from swinge, swingeing; from tinge, tingeing; that they may not be confounded with singing, swinging, and tinging. 3. To compounds and prefixes, as firearms, forearm, anteact, viceagent, the rule does not apply; and final ee remains double, by Rule 6th, as in disagreeable, disagreeing.
RULE X.—FINAL E.
The final e of a primitive word is generally retained before an additional termination beginning with a consonant: as, pale, paleness; edge, edgeless; judge, judgeship; lodge, lodgement; change, changeful; infringe, infringement.