[*] 25. A Root is the simplest form attainable by analysis of a word into its component parts. Such a form contains the main idea of the word in a very general sense, and is common also to other words either in the same language or in kindred languages.1 Thus the root of the stem vōc- is voc, which does not mean to call, or I call, or calling, but merely expresses vaguely the idea of calling, and cannot be used as a part of speech without terminations. With ā- it becomes vocā-, the stem of vocāre (to call); with āv- it is the stem of vocāvit (he called); with āto- it becomes the stem of vocātus (called); with ātiōn- it becomes the stem of vocātiōnis (of a calling). With its vowel lengthened it becomes the stem of vōx , vōc-is (a voice: that by which we call). This stem vōc-, with -ālis added, means belonging to a voice; with -ŭla, a little voice.
[*] Note.--In inflected languages, words are built up from Roots, which at a very early time were used alone to express ideas, as is now done in Chinese. Roots are modified into Stems, which, by inflection, become fully formed words. The process by which roots are modified, in the various forms of derivatives and compounds, is called Stem-building. The whole of this process is originally one of composition, by which significant endings are added one after another to forms capable of pronunciation and conveying a meaning.
Roots had long ceased to be recognized as such before the Latin existed as a separate language. Consequently the forms which we assume as Latin roots never really existed in Latin, but are the representatives of forms used carlier.