In the sentence “He is quick,” the adjective “quick” describes the pronoun “he.” If the sentence changes to describe something he does, such as “he works quickly,” the adverb “quickly” is used because it modifies the verb “works.” In English, many adverbs are created by adding the suffix “–ly” to an adjective. Many adverbs in Spanish are created by adding the suffix – mente to the end of an adjective. When you see a Spanish word that ends in – mente, try picturing “–ly” on the end of the word and you may recognize a simple cognate that looks very similar to its English equivalent.
In both languages, there are some adverbs that are simple, independent words, but many adverbs are based on an adjective. To create this type of adverb in Spanish, you must use the feminine form of the adjective, if it exists. For example, the word finalmente, does not have a feminine form. The basic rules for creating the feminine form of adjectives are included with the examples in this section.
Add – mente to the end of the singular, feminine form (whenever possible) of an adjective, and you have an adverb. Adverbs do not vary in form even though you must use the feminine form of the adjective to create the adverb. Table 1 uses several examples to demonstrate how to create an adverb from an adjective that ends in – o.
An adjective that ends in an – e is the same in its feminine form, so you just need to add – mente to make it into an adverb, as shown in Table 2.
An adjective that ends in a consonant normally does not add an – a to the end to make it feminine (unless it is an adjective of nationality). Therefore, as you can see in Table 3, you just add – mente to an adjective that ends in a consonant to make the adverb form.
Notice in the following examples that an adverb created from an adjective that has a written accent mark will retain the same written accent.
A few specific adverbs have no suffix and are identical to the adjective. The following words can be used as adjectives or adverbs. When used as adverbs, they look like a singular masculine form of the adjective, but since they actually modify a verb, they do not have gender and will not change endings.
Table 4 shows those words in action as an adverb and as an adjective.
Irregular adverb
There is one irregular adverb that is troublesome in both languages. The adverb form of “good” is “well,” which is irregular in English. Not only is the adverb “well” formed irregularly, but the adjective form “good” is often used incorrectly to modify verbs. To describe a noun or a pronoun, you must use the adjective “good.” To describe a verb, you must use the adverb “well.”For example, “The book is good” uses the adjective “good” to modify the noun “book.” In “The author writes well,” the adverb “well” modifies the verb “writes.” It is common to hear the incorrect sentence, “he writes good.” The same problem occurs in Spanish. The word bueno is the equivalent to the English adjective “good,” and the adverb form of bueno is irregular, also. The adverb bien is the equivalent to the English adverb “well.”
A similar phenomenon occurs with the adjective malo (bad) and the adverb mal (badly). It is somewhat easier to remember that malo is the adjective form because it ends in – o, so you would have to determine the gender of the noun it modifies in order to use the right form of the adjective. If you can't find a noun and realize that malo modifies a verb, you must use the adverb mal instead.
In the following examples, notice that mejor (better) and peor (worse) are extremely unusual. The same word can be used as an adjective or adverb, but it does not change endings when used as an adverb.