Adverbs are words that you add to a verb to show how an action is done. In English they often end in -ly. In Spanish they end in -mente. Just like in English, to make an adverb in Spanish you just add -mente to the end of an adjective. There are a couple of things to remember though. If your adjective has an accent mark, you keep it in the same place for the adverb. Also, if the adjective end in an -o, you will need to change that to an –a.
lento (slow) → lentamente (slowly)
hábil (skillful) → hábilmente (skillfully)
claro (clear) → claramente (clearly)
alegre (happy) → alegremente (happily)
rápido (fast) → rápidamente (quickly)
sincero (sincere) → sinceramente (sincerely)
Esa chica habla rápidamente. → That girl talks fast.
There are some words that don’t change and can be used as adverbs or adjectives. Remember that the ending only change when used as adjectives, not adverbs.
más → more
menos → less
poco → little/few
mucho → much
mejor → better
peor → worse
demasiado → too much
Some adverbs don’t follow the -mente pattern.
bueno (good) → bien (well)
malo (bad) → mal (badly)
Es una buena computadora y funciona bien. → It is a good computer and it works well.