Is (hard ) an adverb or adjective?

"Hard" can be used as both an adjective and adverb. As you know, an adjective is a word that adds to, describes  or qualifies a noun whereas an adverb adds to or describes a verb.

Let us look at an example:

Hard as an adjective:

During the practice match, Michael threw a hard pass to the receiver.

(Here, "Hard" describes the noun 'pass' and answers the question "what kind?")

Hard as an adverb:

Michael threw the football hard.

(Here, "Hard" describes the verb threw and answers the question "how?")