A Sentence's Function When It Is Simple

Every sentence in a passage is doing a job, even when there's no word like 'however' or 'for example' announcing it. You find that job by looking at what sits on either side. The sentence before usually sets up a claim, a belief, or a question. The sentence after usually does something with whatever the sentence in question handed it: draws a conclusion, pivots, adds a consequence. The middle sentence is the hinge. Its function is whatever makes that hinge turn — supplying the number a claim needed, the detail an argument leans on, the fact that forces a reversal.

Position changes the job even when the sentence itself doesn't change much. A sentence that opens a paragraph often has to introduce or complicate, because nothing has been said yet for it to react to. The same kind of sentence placed at the end usually has to resolve or conclude, because everything before it has been building toward that spot. So the same kind of content — a statistic, a vivid image, a short claim — can function as a setup in one position and as a payoff in another. This is why the question always asks about function 'in the paragraph' or 'in the passage': location is part of the answer.

This sits right next to the bigger skill of mapping a whole paragraph's shape or a whole passage's structure, because both are built the same way, just at a larger scale. A paragraph's purpose is the sum of its sentences' jobs; a passage's structure is the sum of its paragraphs' jobs. Getting good at naming one sentence's function is the foundation the bigger structural questions rest on.