Topic: Gerunds & Participles,

Best Answer Explained in Below-:

In the sentence "Do you enjoy teaching?", the underlined word "teaching" functions as a gerund. A gerund is formed by adding "-ing" to a verb, turning it into a noun that represents an action or a state. In this case, "teaching," derived from the verb "teach," acts as a noun that refers to the activity of instructing others.

Gerunds can perform various noun functions in a sentence, such as the subject, object, or complement. Here, "teaching" is the object of the verb "enjoy," indicating what is being enjoyed. Although "teaching" retains some characteristics of a verb (it can take direct objects, can be modified by adverbs, etc.), its primary function here is as a noun.

In contrast, the other options do not apply: "teaching" is not a noun in a traditional sense (option A) because it is being used in a specific grammatical role; it is not a participle (option B) because participles act as adjectives, modifying nouns; and it is not an adjective (option D) as it does not describe a noun. Thus, the correct classification of "teaching" in this context is C: a gerund.