The adverbs of manner indicate the way in which an action is performed. They answer questions such as how something is done, and they add a quality to a verb. In María habla claramente, clearly explains the way of speaking. Without that adverb, the sentence remains correct, but it loses precision. They can also modify the whole sentence and give a general evaluation: Fortunately, we arrived on time. Here the adverb does not describe only a verb, but the whole situation.

Manner adverbs do not change gender or number. They are used the same with a feminine or masculine subject, singular or plural. You say rápidamente, rápidamente and rápidamente in all cases. They do not adopt endings like those of adjectives. Therefore forms such as rápida, rápidos or rápidas do not appear when they function as adverbs. Their form remains fixed even if the verb changes: Ella camina lentamente, Ellos caminan lentamente.

Many adverbs of manner are formed from a feminine singular adjective + -mente. If the adjective ends in -o, it first becomes feminine: lento + lentamente, claro + claramente. If the adjective already ends in -e or a consonant, -mente is added directly: feliz + felizmente, suave + suavemente. These adverbs usually keep the accent of the base adjective and are used to specify the way in which the action occurs: Habló claramente, trabajó cuidadosamente.

Some adverbs of manner are fixed words and very common in everyday conversation. Bien expresses a correct or satisfactory way: Cocina bien. Mal indicates an action done incorrectly or insufficiently: Conduce mal. Despacio indicates low speed: Habla despacio. Also appear aprisa, deprisa and regular, depending on context. These words are not formed with -mente and are learned as complete forms.

In everyday speech, certain adjectives are used as adverbs without changing form. In phrases like Habla alto, Camina rápido or Trabaja duro, the words alto, rápido and duro do not describe a noun; they describe the way the action is performed. This form is very common in colloquial Spanish. When the context calls for a more formal or more precise usage, adverbs such as altamente, rápidamente or duramente are usually preferred.

The adverb of manner is often placed after the verb: Respondió calmadamente, cerró la puerta suavemente. It can also go at the start of the sentence to emphasis or change the focus: Suavemente, cerró la puerta. At the beginning, the adverb highlights the manner before presenting the full action. After the verb, the sentence sounds more neutral and direct. When it modifies the entire sentence, it is usually separated with a written or spoken pause: Afortunadamente, todo salió bien.

Manner adverbs can carry intensifiers in front. Muy increases the intensity: muy rápido, muy claramente. Bastante indicates a medium or sufficient degree: bastante bien, bastante despacio. Poco reduces the intensity: poco a poco, poco claramente. These elements are placed before the adverb and form a single idea of degree + manner. In habla muy lentamente, muy does not modify the verb, but the adverb lentamente.