romain

In a sentence

• Les ruines romaines témoignent de la grandeur de l'Antiquité.

  Roman ruins testify to the grandeur of antiquity.

  Here, 'romaines' is an adjective describing 'ruines' (ruins), indicating that they are associated with Rome or the Roman Empire.

• Le style romain de l'architecture est très influent en Europe.

  The Roman style of architecture is very influential in Europe.

  In this sentence, 'romain' serves as an adjective for 'style', specifying that the style pertains to Rome or is characteristic of Roman design.

• Un romain célèbre de l'histoire est Jules César.

  A famous Roman from history is Julius Caesar.

  Here, 'romain' is used as a noun, referring to a person from Rome, and is singular in form.