prepositional phrase

<p>the cost of safely disposing of the toxic chemicals is approximately five times what the company paid to purchase it.</p>

<p>A prepositional phrase must begin with a preposition and end with a noun, gerund, or pronoun.</p>

<p>In this case, I think the "disposing" acts as a verb, or am I wrong???</p>

<p>No, disposing is acting as a noun [gerund].</p>