What are the main themes in "We Real Cool"?
I assume that you are talking about Gwendolyn Brooks' poem by this name. In that poem, the main theme is that a certain group of young men (presumably a subset of African American young men) has cultural values that are destructive. This can be seen most clearly in the last line, where we find out that these guys "die soon."
Brooks is pointing out that the choices these people make and the things that they value lead them to an early grave. She is saying that they (and not society or anyone else) are responsible for their problems.
In this short poem, the members of the group who play pool together at the Golden Shovel reinforce and validate each other's pattern of destructive behavior: dropping out of school, hanging out playing pool, drinking gin, staying up late and "sing[ing]" sin." Brooks emphasizes this sense of group dynamics by having every line of the poem but the last finish on "we." If you listen to her read the poem, you will hear that she stops hard on the "we" at the end of every line, as if to further stress the word, which, in her reading, also functions as a pun: not only is a group of people indicated by "we," but the "we" can sound like the word "whee!" which we might say while having a good time. The poem's ending: "die soon"—indicates that the narrator is aware that the collective behavior in which he participates is destructive. Thus, the theme of the poem, "choose your friends wisely," warns that the people you hang out with might offer you a temporary good time, but can also lead you in the wrong direction. The eNotes summary of the poem also offers good insights.
There are three main themes in Gwendolyn Brooks's poem "We Real Cool": Identification, Mortality, and Musicality.
The voices of "We" are placed as the final word of the end-stopped lines. This significant placement, according to Brooks, makes "we" pronounced softly. Such a low tone to "we" suggests that the boys have their individual identities and possibilities subsumed in their subculture.
Death casts its pall over the inner-city boys who are probably part of a gang. Again the "we" is minimized to the illegal activities of "Strike straight," "Sing sin,"and "Thin gin." They know that they will "Die soon."
The poem contains the rhythm of a jazz tune. The alliteration and internal rhyme lend an almost seductive tone to the poem, suggestive of the physical movement of the gang members, who live in the shadow of crime and childhood dreams unrealized. A short and deceptively simple poem, "We Real Cool" captures in its minimalism the rhythms and experiences of black street life that suddenly give way to greater depths of thought and meaning.