* Gerund: When "selling" acts as the subject of the sentence or the object of a verb or preposition, it's a gerund.
* Example: Selling cars is a competitive industry. (subject)
* Example: He enjoys selling real estate. (object of the verb "enjoys")
* Example: She's good at selling her ideas. (object of the preposition "at")
* Present Participle: When "selling" describes a noun or pronoun, it's a present participle.
* Example: The selling price was too high. (modifies "price")
* Example: The selling agent was very helpful. (modifies "agent")
* Verb: In some contexts, "selling" can be a verb.
* Example: She is selling her house.
It's important to consider the context of the sentence to determine the part of speech of "selling."