Which form of "ridiculous/ridiculously" is correct in this sentence, and why?

Question

This is the sentence in question:

Never would he wish to injure the feelings of his schoolmate of so long ago, no matter how ridiculous/ridiculously he was acting, or how strange his beliefs.

The difficulty seems to arise over figuring out if the verb phrase is was acting, or if the verb is was, which would make acting ridiculous a gerund--or not? Is this the key to figuring out the word form?

Does the author chose the word form in order to tell the reader when the acting was happening in time, or is one form always called for in this arrangement by some solid rule? If so, what IS this arrangement?

Answer 1

A gerund is not the same thing as a present participle even though both terms end in “-ing.”

A gerund always acts as a noun.

A present participle is always part of a verb phrase.

Examples:

Sarah enjoys singing. In this example, “Sarah” is the subject, “enjoys” is the verb, and “singing” is a noun acting as the direct object of the sentence(gerund).

Sarah is singing. In this example, “is singing” is the verb phrase. “Singing” is the present progressive verb, telling what the subject “Sarah” is doing.

Thus in he was acting, was acting acts as a verb phrase and not a gerund.

So,ridiculously is the right option as it is an adverb.