Except adjectives expressing the natives of a country, or things belonging to it; and also most of those terminating in an or on, which add an a for the feminine; as, Spaniard, or Spanish, español, española; idle, haragan, haragana; clamorous, griton, gritona.
Adjectives form their plural according to the rules set forth for the nouns; as, white, blanco, blancos, blanca, blancas; deep blue, turquí, turquíes; natural, natural, naturales; happy, feliz, felices, or felizes.
Uno, one; alguno, some; ninguno, none; primero, first; bueno, good; malo, bad; suppress the o when they are immediately followed by a substantive masculine in the singular, whether it be alone, or preceded by an adjective; as, no heart, ningun corazon; ningun humano corazon.
Ciento, hundred, loses the last syllable before a substantive masculine or feminine; the same does Santo before a noun masculine in the singular. Grande, great, generally loses it also when it refers to qualities; as, El Gran Capitan.
COMPARATIVE.
Greater, mayor; less, menor; better, mejor; worse, peor, superior, superior, &c.
SUPERLATIVE.
It is formed, first, by literally translating the adverb very, muy; as, very high, muy alto. Secondly, by adding the termination ísimo, or ísima, to the adjective, which suppresses the last letter if it be an o, or e: very fine, finísimo; very sweet, dulcisimo; very useful, utilísimo. Adjectives in ble change it into bilísimo; those in co, into quísimo; and those in go, into guísimo; as, amabilísimo, riquísimo, prodiguísimo. Thirdly, by prefixing el, los, la, las mas, or ménos to the adjective; as, The most industrious, El mas industrioso; the most humane, el, or los mas humanos; la, or las mas humanas.
Best, óptimo, worst, pésimo; greatest, máximo; least, mínimo; lowest, ínfimo; supreme, supremo.