Adding – mente to the feminine form of an adjective creates a pretty long word. This creates a rather cumbersome sentence when several adverbs ending in – mente are used in the same sentence, so the Spanish language has a rule to shorten adverbs when more than one is used. When two or more adverbs end in – mente, the suffix – mente is used only with the last adverb, all preceding adverbs lose the – mente and keep the singular feminine form of the adjective.