A sequel to her widely used A Companion to Familia Romana (now in its second edition), Jeanne Marie Neumann's A Companion to Roma Aeterna offers a running commentary, in English, of the Latin grammar covered in Hans H. Ørberg's Roma Aeterna, and includes the complete text of the Ørberg ancillaries Grammatica Latina and Latin–English Vocabulary II. It also serves as a substitute for Ørberg’s Instructions, on which it is based.

Though designed especially for those approaching Roma Aeterna at an accelerated pace, this volume will be useful to anyone seeking an explicit exposition of that volume's implicitly presented grammar. In addition to many revisions of the text, A Companion to Roma Aeterna also includes new units on cultural context, tied to the narrative content of the chapter.