The understanding of theme in a poem
The theme is "underlying message or big idea" depicting in the poem that may be stated directly or indirectly. It is important to note that there is a distinction between the subject and theme of the poem. A subject is generally the topic of the poem or what the poem is all about whereas the theme is an idea that the poem expresses about the subject. For example, in the Edgar Allan Poe poem "The Raven," the subject is the raven, who continually repeats a single word in response to the speaker's questions. The theme of the poem, however, is the irreversibility of death -- the speaker asks the raven, in a variety of ways, whether or not he will see his dead beloved again, to which the raven always replies "nevermore." The theme of a poem may be stated explicitly, but more often, it is implicit.