When you use an adjective in front of a verb?

Adjectives aren't used in front of verbs.

Adjectives are used to describe nouns and they go in front of the noun. eg

adjective = black, noun = dog. The black dog bit my hand.

Adverbs are associated with verbs. They add information about verbs. eg

adverb = always, verb = get. I always get the bus to work.