Does the sentence a snake moved slowly through the grass have an adverb and an adjective?

The (article) snake (noun) moved (verb) slowly (adverb) through the grass (prepositional phrase).

This sentence doesn't have an adjective, because an adjective describes a noun, pronoun, or other adjective.

If you said "The snake moved slowly through the green grass," green would be the adjective because it is describing the Word, "grass", which is a noun.