Frank Edgar Farley, An Advanced English Grammar with Exercises
“ INFLECTION OF VERBS 216. Verbs have inflections of tense, person and number, and mood. They also have the distinction of voice, which is expressed by the help of verb-phrases.Tense indicates time; person and number correspond with person and number in substantives; mood shows the manner in which the action is expressed; voice indicates whether the subject acts or is acted upon. ”
