Is the group of words in bold a phrase or a clause?

By refusing to surrender her seat to a white passenger, African American activist Rosa Parks inspired a boycott of city buses in Montgomery, Alabama, and helped strengthen the civil rights movement.

1 answer

The group of words in bold, "By refusing to surrender her seat to a white passenger," is a phrase. Specifically, it is a gerund phrase, as it begins with the gerund "refusing" and functions as a prepositional phrase indicating the manner in which Rosa Parks inspired the boycott. It does not contain a subject-verb combination, which is characteristic of a clause.