This is the 9854th most frequent French word.
fast
The French word "fast" does not exist; it is an English word. In French, equivalent terms might be "rapide" (quick) or "vite" (quickly).
The word 'vite' is used as an adverb to describe the speed of action conveyed by the verb 'to run'.
Elle court vite pour attraper le bus.
She runs fast to catch the bus.
The word 'rapide' is employed as an adjective to describe the quick nature of the noun 'car'.
Cette voiture est très rapide.
This car is very fast.
Here, 'de manière rapide' acts as an adverbial phrase providing context to the manner in which the verb 'ate' took place.