Of course when a soft _g_ precedes the doubtful letter, as in _legible,_ we are always certain that we should write _i,_ not _a_. All words formed from plain English words add _able_. Those familiar with Latin will have little difficulty in recognizing the _i_ as an essential part of the root.
Words ending in ent and ant, and ence and ance.
Another class of words concerning which we must also feel doubt is that terminating in _ence_ and _ance,_ or _ant_ and _ent_. All these words are from the Latin, and the difference in termination is usually due to whether they come from verbs of the first conjugation or of other conjugations. As there is no means of distinguishing, we must continually refer to the dictionary till we have learned each one. We present a brief list:
ent confident belligerent independent transcendent competent insistent consistent convalescent correspondent corpulent dependent despondent expedient impertinent inclement insolvent intermittent prevalent superintendent recipient proficient efficient eminent excellent fraudulent latent opulent convenient corpulent descendent different ant abundant accountant arrogant assailant assistant attendant clairvoyant combatant recreant consonant conversant defendant descendent discordant elegant exorbitant important incessant irrelevant luxuriant malignant petulant pleasant poignant reluctant stagnant triumphant vagrant warrant attendant repentant
A few of these words may have either termination according to the meaning, as _confident_ (adj.) and _confidant_ (noun). Usually the noun ends in _ant,_ the adjective in _ent_. Some words ending in _ant_ are used both as noun and as adjective, as _attendant_. The abstract nouns in _ence_ or _ance_ correspond to the adjectives. But there are several of which the adjective form does not appear in the above list:
ence abstinence existence innocence diffidence diligence essence indigence negligence obedience occurrence reverence vehemence residence violence reminiscence intelligence presence prominence prudence reference reverence transference turbulence consequence indolence patience beneficence preference ance annoyance cognizance vengeance compliance conveyance ignorance grievance fragrance pittance alliance defiance acquaintance deliverance appearance accordance countenance sustenance remittance connivance resistance nuisance utterance variance vigilance maintenance forbearance temperance repentance