Question

is the group of words in bold a phrase or a clause? the role of a prosecutor is to present a court case against an accused offender.

Explanation:

First, we need to identify the bolded group of words (assuming "to present a court case against an accused offender" is the bolded part, or if it's another group, but from the sentence, let's analyze. A phrase is a group of words without a subject - predicate relationship, while a clause has a subject and a predicate. The group "to present a court case against an accused offender" is an infinitive phrase. It does not have a subject - predicate structure (there's no subject doing a verb in the traditional clause sense here; "to present" is an infinitive, not a finite verb with a subject). So it's a phrase.

Answer:

It is a phrase.