How do you find the main idea in a GED reading passage?

Almost every reading question gets easier once you know what the passage is mostly about. That is why finding the main idea is worth practicing on its own. It is a skill the GED tests directly.^[1] It also gives you a map for every other question about the same passage.

This post explains what the main idea is, how it differs from details, and a simple four-step way to find it, with short made-up examples you can practice on.

What the GED asks you to do

The GED Language Arts test names main ideas in more than one of its official reading skills:

• Understanding the details and main ideas stated in a text is an official skill.^[1]
• The test also asks you to work out a main idea that is implied, not stated, in a paragraph or a whole text.^[1]
• A related skill is choosing which details support a given main idea.^[1]

GED lists inferring implied main ideas as a skill you need to build to move from Below Passing to the passing level.^[2] You will be asked to find the main idea in texts that range in difficulty, up to the college and career ready level.^[3] Reading passages on the test are 400 to 900 words long.^[3] So the skill has to work on long texts, not just single paragraphs.

Main idea and details: what is the difference?

The main idea is the one big point a passage makes. Details are the smaller pieces, such as facts, examples, reasons and short stories, that explain or back up that point.

Here is a short paragraph we made up for practice:

Our building's laundry room used to be a mess. Two of the four washers broke down almost every week, and the floor was often wet. Last spring, a few tenants formed a small committee. They asked the owner for new machines, set up a cleaning schedule and posted the rules by the door. Now the room stays clean, and every machine works.

The main idea: a group of tenants got the laundry room fixed. The details are the broken washers, the wet floor, the committee, the new machines, the schedule and the rules.

Notice that no single detail is the main idea. The broken washers are part of the story, but the paragraph is not mostly about washers. It is about how the tenants turned the room around.

Step 1: Read the opening closely

If a text has no headings, read the opening paragraphs closely first, because they usually set out what the text will argue.^[4] On a long passage, a careful read of the first paragraph or two gives you a working guess about the main idea. Keep that guess in mind as you read the rest, and change it if the passage goes somewhere new.

Step 2: Look for topic sentences

A topic sentence is a sentence that tells, in a general way, what idea the paragraph is about.^[5] Most often, the topic sentence is the first sentence of the paragraph.^[6] But a topic sentence can be anywhere in a paragraph: first, last, or in the middle.^[5]

Here is a made-up paragraph with its topic sentence at the end:

The morning bus came twelve minutes late on Monday. On Tuesday, it skipped our stop. On Wednesday, it was so full that the driver waved us on. This week made one thing clear: our street needs a second morning bus.

The last sentence is the topic sentence. The three sentences before it are details that lead up to it. If you only read the first sentence, you might think the paragraph is about one late bus, and you would miss the point.

Step 3: When no sentence says it

Sometimes the main idea is unstated: no sentence says it, so you read over the details and ask what they all talk about.^[6] This is the skill GED calls inferring an implied main idea.^[1]

Look back at the laundry room paragraph. No sentence says, "A group of tenants got the laundry room fixed." But every detail points there. A good question to ask is: what do all of these details have in common? The answer to that question is usually the implied main idea.

Step 4: Say it in your own words, then test the choices

Before you look at the answer choices, put the main idea into one sentence of your own. Then test each choice against the whole passage, not just one paragraph.

GED's own advice for questions that ask you to infer is to cross out answers that go beyond what the passage supports.^[7] That advice fits implied main ideas too, because working out an unstated main idea is a kind of inference.

When you test the choices, watch for a few kinds of wrong answers. Here they are, using the laundry room paragraph:

• Too narrow: a true detail from one part of the passage. "Two of the four washers broke down almost every week."
• Too broad: a big claim the passage never makes. "Every apartment building should have a tenants' committee."
• Twisted: a choice that uses words from the passage but changes what they mean. "The owner fixed the laundry room on his own."
• The main idea: a choice that covers the whole passage. "A group of tenants got the laundry room fixed."

Try it yourself

On OpenEssayMe, the free main idea practice question uses a short article about street trees. Read the article, use the four steps, pick your answer, and then read the feedback, which explains every choice. For more questions with the same kind of feedback, visit free practice.