This is the 1485th most frequent Spanish word.
rápido
Fast; quick.
In this sentence, 'rápido' is used as an adjective describing the noun 'coche' (car).
El coche es muy rápido.
The car is very fast.
Here, 'rápido' functions as an adverb modifying the verb 'corre' (run), describing the manner of the action.
Corre rápido para llegar a tiempo.
Run quickly to arrive on time.
'Rápido' in this sentence is used as an adverb associated with the verb 'aprender' (learn), indicating the speed of the learning process.