Adjectives as adverbs
Some adverbs have the same form as the masculine adjective, but remain invariable.
Some examples:
Limpio – fair
Bajo – quiet
Rápido – fast
Claro – clearly
Alto – loud
The difference between adverbs and adjectives is basically that adjectives refer to a noun and are changeable. Adverbs are unchangeable.
Franco tiene un departamento muy limpio.
Franco juega siempre limpio.
Tus ideas nos on claras.
No hablas claro.