For examle in Latin, the noun amicus has the root amic, the adjective magnus has the root magn. But did the average romans really understand these roots? Could they understand their meaning by hearing the roots only, rather than hearing their nominative case?

What is the root of the Latin word elementum and its meaning? Why does the Greek word for element differ and what is its root and its meaning? Why does Euclid use Latin for the title of his book on geometry and not Greek?