Could the alarm have failed to ring? What is the verb phrase in this sentence?

In the question, "Could the alarm have failed to ring?" the verb phrase is "failed to ring."

Explanation:

A certain portion of a statement which consists of an object, direct or indirect and a verb. It bridges the subject of the verb with the information that the subject is offering, then it serves the purpose of a verb phrase. It can be the predicate of a sentence or a certain clause. It can also operate as an adverb or adjective, and at the same time comprise of a verb and its objects, modifiers and other segments.