The phrase "under the stove" functions as an <em>adjective</em>. It describes the noun "drawer" and answers the <em>adjective</em> question "Which one?"
An <em>adjective phrase</em> is a <em>prepositional phrase</em> that modifies a <em>noun</em> or a pronoun.
The phrase under the stove is a prepositional phrase because it includes a preposition, <em>under</em>, and an object of the preposition, <em>stove</em>, plus the modifier, <em>the</em>. This phrase modifies, or describes, a noun, drawer; therefore, it is an adjective phrase.
