How do I compare and contrast the tones of these three poems from Langston Hughes: I, Too, Negro Speaks of Rivers, and Theme for English B?I need...

I agree with what the previous poster says, but I would encourage you to begin answering your question by defining the word "tone" for your own purposes. "Tone" is not the same as "theme," for example; all three poems can indeed be read as addressing the black person's place in contemporary society, but the poems differ significantly in tone. You will probably want to look up defnitions of the term "tone" in several sources and pay paticular attention to key words in the different definitions.

For example, one internet source, cited first below, defines tone as "the author’s attitude, stated or implied, toward a subject. Some possible attitudes are pessimism, optimism, earnestness, seriousness, bitterness, humorous, and joyful. An author’s tone can be revealed through choice of words and details." A second internet source, cited second below, defines tone as "the author’s implicit attitude toward the reader or the people, places, and events in a work as revealed by the elements of the author’s style. Tone may be characterized as serious or ironic, sad or happy, private or public, angry or affectionate, bitter or nostalgic, or any other attitudes and feelings that human beings experience. See also style."

In comparing these definitions, you may note several key terms: "attitude" is used in both definitions but "style" is only used in one. One definition uses the words "stated or implied" while the other only uses the word "implicit" (which means pretty much the same as "implied"). While terms in these definitions do overlap, the two definitions are not identical. You may find one definition more useful than the other for answering your questions. (Of course, you may also find other, perhaps superior definitions of the term "tone.")

At this point, you can rephrase your initial question to read: How does the attitude of the speaker differ in these three poems? or How does the speaking style of the speaker differ in the three poems?

Here are some initial, quick comments and observations that may get you started:

On attitude: There seems to me to be some "attitude" (in the sense of sassiness or spirit) in the "I, Too" (especially in the final lines of the poem) and perhaps even more in "Theme for English B." In comparison to those poems, "The Negro Speaks of Rivers" seems to have a very somber or serious tone.

On style: The grammar and word choice of "The Negro Speaks of Rivers" seems to me the most formal of the three. There's no slang or colloquial speech in this poem. To me, this poem also seems the most highly structured. It's about as close as Hughes gets to writing formal poetry.

These observations lead me to think that we can place these poems on a scale from serious to playful (or from sombre to sassy, if you prefer), with "The Negro Speaks of Rivers" on the serious side, "Theme for English B" on the playful side, and "I, Too" somewhere in between. To support such a placement, of course, we should reread each poem carefully and be ready to present evidence from each poem (e.g. specific words or phrases, grammar, direct or indirect expressions of the speaker's views, etc.).