The best way to determine tone in "A Rock Trying to Be a Stone" and "Guests of the Nation" is to examine diction and syntax. For example, in "A Rock," the diction reflects the socioeconomic status of the barely educated youths dealing with a brutal lack of opportunity: the narrator holds most emotion in check, stating facts coldly, objectively. In "Guests," the diction reflects the narrator's generally pleasant emotion as he describes people and events, beginning his story with "Well, chums...?" Syntax elements are different in each, the first having short, choppy sentences, and the second having longer, more flowing sentences.
Tone is the attitude, perspective, and emotion that the speaker has toward the subject matter being written about. Tone is detected in the diction a speaker uses and elements of syntax. To avoid a mistake often made, remember that tone is not detected in setting. Setting reveals something very different from tone: mood. Setting establishes mood within the story; diction and syntax establish author tone external to the story. Tone descriptors identify attitude (a way of thinking reflected in behavior), perspective (point of view regarding something), and emotion (feeling occurring toward someone, something, or some occurrence). Tone may be critical and subjective or critical and objective; it may be solemn or cynical. Tone may also be humorous or straightforward (think of "Garfield" compared with an economics textbook).
The clearest connection of diction to conflict and theme appears in the titles of both short stories. In "A Rock Trying to Be a Stone," the difference between a rock and stone highlights both conflict and theme as Turi tries to understand and do right in an environment that doesn't offer much opportunity for either. He is a rock trying to be a [gem] stone in a rocky environment. In "Guest of the Nation," the difference between guest and hostage dramatizes the conflict and theme as "chums" have to choose between duty to friends and duty to country. The bitterly ironic contrast between a guest protected by the nation and a hostage shot by the nation highlights the struggle the men are going through.