The answer is: it helps the reader understand how frightening the word is.
In the excerpt from the poem "Can't," by Edgar Albert Guest, the author makes reference to the terror of the word "can't." He describes it as the creator of weak effort, intense fear and unenthusiastic work. In the other lines, Guest claims that "can't is the worst word that's written or spoken," and depicts it as harmful for the soul, since it takes away people's courage, hopes and dreams.
Exceptional and common...........
Glucose and oxygen are the input
