Diction specifically refers to a writer's word choices, and diction is used to develop the writer's themes, tone, mood, and overall style. Within the English language, many word choices exist to describe the same object or paint the same picture, but one word choice over another creates a specific and desired effect and represents an author's diction (Dr. Wheeler, Literary Terms and Definitions: D, "Diction"). Her diction is formal, strongly poetic, yet conversational.
In her poem titled "Because I could not stop for Death--," Emily Dickinson strives to describe death as inescapable and to paint the tone of passive acceptance while maintaining a contrast between life and death that could be depressing but is not due simply to Dickinson's word choices, her diction. Her use of diction serves to accomplish all these things.
One example of very noticeable diction concerns the use of the very simple yet powerful verb "stop." In the very first stanza, she captures death as a stopping, as a cessation of all things by using the verb "stop." She also paints the contrast between life and death by stating, "Because I could not stop for Death-- / He kindly stopped for me--" In other words, the speaker's life was so busy that she had not time to think of death, which shows a contrast between living life and inevitable death. In addition, her statement that Death stopped for her helps portray death as inescapable.
In the third and fourth stanzas, her choice to use the verb "passed" helps paint life as something that inevitably passes us by due to death being inescapable, which helps establish the theme of death being inescapable. In addition, as the speaker describes passing a school where children play, passing grain fields, and passing the setting sun, the reader is drawn to the images of life, which helps the reader see the contrast Dickinson is creating between death and life. However, despite the contrast she constructs between life and death, she maintains an accepting tone throughout, which is created by intentionally refraining from using diction that will capture feelings of sorrow or lamentation.