In English, adverbs can be created from many adjectives simply by adding "-ly" at the end. In Spanish, it's almost as easy.

The basic rule is that the suffix -mente is added to the end of the feminine, singular form of the adjective. Generally, the feminine, singular form of the adjective is the same as the "regular" or masculine, singular form unless the adjective ends in an o, in which case the -o is changed to an -a.

See the following examples:

Note, as in two of the examples above, that if an adjective has an accent mark, the corresponding adverb retains the accent mark, even though the spoken emphasis likely will be on the next-to-last syllable.

A final note: When two adverbs are used in a series, the -mente suffixed is dropped from all but the last adverb.

• Habla lenta y claramente. She speaks slowly and clearly.
• Anda cuidada, dificultosa y pacientemente. He walks carefully, difficultly and patiently.