Why Does the Author Mention X? A 3 Question RC Check

VARC

Few RC questions feel as slippery as the one that begins, why does the author mention this? You can recall the detail. You can even paraphrase the sentence around it. And still three options look equally defensible, because each describes something the detail could be doing in a passage.

The problem is that you are being asked about function, not content. A function question wants to know what a sentence is for, what job it does in the argument. This guide gives you a three-question check that finds that job quickly, with a short worked passage so you can see the check run end to end.

Why Function Questions Trip Up Good Readers

Good readers are often better at content than at function. They understand a paragraph, remember its examples and can restate its claims. A function question asks something different. It asks you to treat the passage as a machine and say which part does what.

That shift matters because the wrong options are built from content. They restate what the detail says, or attach a plausible message to it. If you answer by asking which option sounds true about the detail, you will often pick a wrong one, since many of them are true of the detail and false of its role.

The cure is to separate two questions in your head. What does this sentence say? And what is it doing for the argument? Only the second matters here. The check below turns the second question into three smaller ones you can answer quickly, even on a passage you found hard.

The Function Check: Three Questions in Order

The Function Check runs in the margin of the passage, in about twenty seconds. It works because every detail in a good argumentative passage is there for a reason, and the reason is almost always tied to a claim within a sentence or two.

The three questions are ordered from concrete to abstract. The first sends you back to the page. The second is a thought experiment that exposes what the detail contributes. The third gives you the verb that should match the correct option. If you can finish the sentence, the author mentions X in order to, you are ready to look at the options.

A Worked Passage with the Check Applied

Here is a short passage written for practice. Supporters of rooftop beekeeping point to the sheer number of hives on city towers as proof that urban ecology is thriving. Yet the number of hives is a poor measure. Paris, which hosts several hundred, offers its bees little forage beyond ornamental trees, and wild pollinators there have declined. Honeybees, in effect, compete with the very species the movement claims to protect.

The question asks why the author mentions Paris. Start with the claim. The nearest claim is that the number of hives is a poor measure of ecological health. Now delete Paris. The author would be left with an assertion and no evidence for it. So Paris is there to give an instance where many hives coexist with poor outcomes for wild pollinators.

The role is to illustrate, and in particular to support a rebuttal of the supporters' claim. The best option would say something like: to show that a large number of hives can exist alongside harm to other pollinators. A tempting wrong option says Paris is mentioned to show how widespread beekeeping has become. That is true of the detail, and false of its job.

Try a second case, where the role is a concession. Imagine a passage that says: admittedly, rooftop hives do raise public awareness of pollinators, but awareness is not habitat. If a question asks why the author mentions public awareness, the nearest claim is that awareness is not habitat. Delete the awareness clause and the author loses the point being granted. The role is to concede a benefit before arguing it is insufficient, and an option saying the author praises the practice would be the inflated trap.

Role	Common signal	Option wording to expect
Illustrate	For instance, consider, a case in point	To exemplify a general claim
Support	Because, evidence shows	To provide evidence for a claim
Contrast	Yet, unlike, by contrast	To set up a difference
Concede	Admittedly, it is true that	To grant a point to the opposing side
Qualify	Although, in some cases	To limit the scope of a claim

Reading the Signals That Reveal the Role

Passages give away the role of a detail through small words. A for instance or consider announces an illustration. A yet or however announces a turn, so the sentence before it has probably been set up to be questioned. An admittedly or granted marks a concession, where the author gives ground in order to make the next point stronger.

Concessions deserve particular attention because they invert the usual reading. A detail that sounds supportive of the opposing view may be there as a concession, not as the author's position. If you take it at face value, you will assign it the wrong job. Check the sentence that follows, since the author usually pivots straight after granting the point.

Qualifications work in the opposite direction. They narrow a claim without abandoning it. A phrase like in some cases or at least for now limits how far the claim reaches. If a detail appears right after such a phrase, its role may be to mark the edge of the claim, not to prove it.

Not every passage has signal words, so keep the deletion test as your fallback. Ask what the claim loses if the detail goes. If the claim loses its only evidence, the role is to support. If it loses a contrast, the role is to set up a difference. If it loses nothing, the detail may be there for colour, and options that overstate its importance are suspect.

How Wrong Options Are Built

Understanding how the wrong options are built makes them easier to reject. Function questions usually have three kinds of trap. The first is the content restatement, an option that says what the detail says and nothing about why it is there. These feel safe because they are true, but they do not answer the question.

The second is the inflated role. The option gives the detail a job that is bigger than the passage supports, such as saying the example proves a general law when the author only offers it as one case. The third is the wrong direction. The option assigns the detail to the opposite side of the argument, for example calling a concession the author's own evidence.

A quick screen helps. For each option, ask whether it names a job or merely describes content. Discard the content-only ones. Then ask whether the job is the right size, and whether it points the right way in the argument. Usually one option survives, and it is the one that matches the role verb you found with the check.

These traps overlap with those in other question types. Our guide on EXCEPT and NOT questions in CAT RC shows how option-by-option checking works under a different question stem, and the same habit of testing each option against the passage applies here.

Build the Habit with Your Own Wrong Answers

The Function Check is easiest to learn from mistakes you have already made. Go back to your last ten function questions, including the ones you got right by guessing. For each, write the nearest claim and the role verb, and compare them with the option you picked. Look for patterns, such as always choosing content restatements.

That kind of review is slow the first time and quick after a few rounds. If you want a structured way to do it, our guide to reviewing a wrong RC answer in five steps shows how to trace an error back to its cause, and the RC skeleton method helps you see which sentences carry the argument and which carry only examples.

If you would like feedback from someone who has coached many aspirants, you can talk to a CAT mentor about how you read passages, and use a CAT study planner to give short, regular RC sessions a place in your week.