Finding the main idea
The main idea is what the whole text is mostly about, not the most interesting detail in it.
Main idea versus detail
A detail sits in one sentence. The main idea runs through all of them.
In the passage below, three sentences are about bees mattering to the food we grow. One sentence tells you a hive can hold 50 000 bees — true, and interesting, and not what the text is about.
The one-sentence test
Ask yourself: if the writer had only one sentence left, what would they keep?
That is the main idea. Everything else is there to explain it, prove it, or make it interesting.
Why the wrong options are tempting
Wrong answers are usually true. That is what makes them hard.
They take a real detail from the text and offer it back to you, and it feels right because you remember reading it. Check its reach: does it cover the whole text, or only one sentence of it?
Too narrow, too wide, or just right
Wrong answers here come in two flavours, and naming which is which makes them easy to reject.
Too narrow means true, but only about one sentence. If a text on bees spends four paragraphs on pollination and one line on honey, "bees make honey" is too narrow.
Too wide means bigger than the text. "Insects are important" may be perfectly true, but if the text only discussed bees, it claims ground the text never covered.
Where the main idea usually hides
In most short texts it is the first sentence or the last. Writers tend to announce what they are about, or sum it up at the end.
If neither says it outright, look at what every paragraph has in common. The main idea is the thing they are all evidence for.
A useful check: cover the options and say the point out loud in one sentence of your own. Then pick the option closest to what you said, rather than reading four options and talking yourself into one.
Worked examples
A text explains that bees visit hundreds of flowers a day, carry pollen between them, and that many crops would fail without them. It also mentions a hive can hold 50 000 bees. What is the main idea?
Three of the four sentences are about what bees do for plants and crops. The hive size appears once and nothing else depends on it. So the main idea is that bees matter to the food we grow, and 50 000 is a detail.
Answer: Bees are important to the crops we grow
A text describes how a girl trains every morning, gives up weekends, and finally wins her race. Is "she won the race" the main idea?
It is the ending, not the idea. Most of the text is about the work she put in, so the point is that her hard work paid off. Winning is the last detail, not what the text is built on.
Answer: No — the main idea is that her hard work paid off
How can you tell a main idea option is too narrow?
Hold it against each sentence in turn. If most of them have nothing to do with it, the option is covering one corner of the text and not the text itself.
Answer: Most sentences do not relate to it
A text describes how a city built bike lanes, how cycling rose, and how traffic fell. What is the main idea?
Every paragraph is evidence for the same thing: the bike lanes changed how people travel. An option about traffic alone would be too narrow, one about cities in general too wide.
Answer: The bike lanes changed how the city travels
Why is "Animals are interesting" a poor main-idea answer for a text about penguins?
It is too wide. The text gave evidence about penguins only, so an option covering all animals claims more than the text supports.
Answer: It is far wider than the text
A text has five paragraphs and one option repeats paragraph two exactly. What is wrong with it?
It is too narrow. It is true, but it leaves out four fifths of the text, so it cannot be what the whole text is about.
Answer: It covers only one paragraph
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