Question

we all agree that martins singing is the best. gerund participle infinitive

Explanation:

In the sentence "We all agree that Martin's singing is the best", "singing" functions as a gerund. A gerund is a verb - ing form that acts as a noun. Here, "Martin's singing" is a noun phrase where "singing" is the gerund (it is the subject of the subordinate clause "that Martin's singing is the best" and functions as a noun, representing the action of singing as a thing). A participle is a verb - ing or verb - ed form that acts as an adjective, and an infinitive is in the form of "to + verb". Since "singing" here is acting as a noun, it is a gerund.

Answer:

gerund