Here are 10 facts about Spanish adverbs that will come in handy to know as you learn Spanish:
1. An adverb is a part of speech that is used to modify the meaning of an adjective, verb, another adverb or an entire sentence. In other words, adverbs in Spanish have basically the same function as they do in English.
2. Most adverbs are formed by taking the singular feminine form of the adjective and adding the suffix -mente. Thus -mente is usually the equivalent of the "-ly" ending in English.
3. Many of the most common adverbs are short words that don't end in -mente. Among them are aquí (here), bien (well), mal (poorly), no (not), nunca (never) and siempre (always).
4. Regarding placement of adverbs, adverbs that affect the meaning of a verb usually go after the verb, while adverbs that affect the meaning of an adjective or another adverb are usually placed in front of the word they refer to.
5. It is extremely common in Spanish to use an adverbial phrase, usually a phrase of two or three words, where an adverb might be used in English. In fact, in many cases Spanish speakers often prefer adverbial phrases even where a corresponding adverb exists. For example, while the adverb nuevamente, meaning "newly" or "anew," is readily understood, native speakers are much more likely to say de nuevo or otra vez to mean much the same thing.
6. In a series of adverbs that end in -mente, the -mente ending is used on only the final adverb. An example would be in the sentence "Puede compartir archivos rápida y fácilmente" (You can share files quickly and easily), where the -mente is "shared" with rápida and fácil.
7. Some nouns act as adverbs even though you might not think of them that way. Common examples are the days of the week and the months. In the sentence "Nos vamos el lunes a una cabaña en el campo" (We're going away Monday to a cabin in the country), el lunes is functioning as an adverb of time.
8. Occasionally, singular masculine adjectives can function as adverbs, especially in informal speech. Sentences such as "canta muy lindo" (he/she sings beautifully) and "estudia fuerte" (he studies hard) can be heard in some areas but sound wrong or overly informal in other areas. Such usage is best avoided except in imitation of native speakers in your locality.
9. Adverbs of doubt or probability that affect the meaning of a verb often require the affected verb to be in the subjunctive mood. Example: Hay muchas cosas que probablemente no sepas sobre mi país. (There are many things you probably don't know about my country.)
10. When no or another adverb of negation comes before a verb, a negative form can still be used afterward, forming a double negative. Thus a sentence such as "No tengo nada" (literally, "I don't have nothing") is grammatically correct Spanish.