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Chapter 3: Writing Mechanics Help
Chapter 12: Teaching Writing
Chapter 23: Teaching Reading
College English Composition: Help and Review
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What is Main Idea and Supporting Details?

Every piece of writing should have both a main idea and supporting details. What is the main idea and supporting details?

Main idea is the number one thing a writer wants the audience to understand after reading. It can also be referred to as the main point. In a fictional piece, this is often found by asking, “what happened?” In non-fiction, it is the main point a writer is trying to prove.

Supporting details are information, details, or points of discussion that prove the main idea. The bulk of any piece of writing is made up of these supporting details. In fiction writing, supporting details include the characters, plot details, and setting details. In non-fiction, supporting details can take many different forms such as statistics, examples, history, or logical analysis, among many others. They all are included to help the reader establish a clear understanding of the main idea.

Finding the main idea and supporting details can help a reader enjoy a story.

Woman reading a book

Main Idea versus Plot and Theme

Plot refers to what happens in a story. It can be thought of as a timeline, although events do not always start at the earliest point in time and end at the latest. To determine plot, readers may ask themselves, “what is the story about?” The plot often acts as supporting details for the main idea.

Theme refers to the overall message a writer is intending to convey throughout a fictional piece of writing. It can be thought of as the deeper meaning of a piece of writing. It is the moral of a story. To determine what the theme is, readers can ask themselves, “what is the message?” Oftentimes a theme can be expressed in one or two words.

Main Idea refers to what the story is mostly about. It is the overall idea of the story. A main idea is often expressed in one or two sentences.

Looking at the story, Cinderella, can help clarify the differences between theme and main idea.

The main idea of Cinderella is that a young girl is left with her wicked stepmother until she has a magical night and wins the hand of the prince.

That one sentence explains essentially what happens in the story. We find this main idea by looking at the plot and distilling it down to one or two sentences.

There are multiple themes in Cinderella. Loyalty, kindness, and the triumph of good over evil are all themes in the story. We determine these themes by looking at the supporting details. Those details in this case are provided in the plot. We learn that the themes are loyalty and kindness and the triumph of good because those are traits Cinderella exhibits throughout the story. She is kind to the animals, and ultimately she wins the hand of the prince.

Through the above, we can see that the main idea is what happened and the theme tells us why that is important. The plot provides us with details to help us determine both the main idea and theme.

Identifying the Main Idea and Supporting Details

We have seen how a reader can identify the main idea and supporting details. This is important to do because we cannot understand what happens in a story without knowing these two things. They are the essence of what any story is about, and we can neither enjoy nor fully understand a story without identifying them.

Continuing with the story of Cinderella, the following are supporting details:

  1. Cinderella’s father dies
  2. Cinderella’s step mother and step sisters are unkind to her.
  3. A prince cannot find a woman to marry so his father throws a ball where he must find a wife
  4. Cinderella manages to attend the ball and the prince falls in love with her.

There are many more supporting details in the story, but these are some of the main ones to illustrate the concept of supporting details.

Without the supporting details, there is nothing to the story. Without the main idea, there is no point to the story.

The same is true about a piece of non-fiction. The main idea is the number one thing a writer is trying to convey, or prove, to the reader. Supporting details include all the ways the writer tries to prove this main idea.

A reader can locate a main idea and supporting details in both fiction and nonfiction writing


Identifying the Main Point

The main point, or main idea, is what the writing is about.

When trying to find and articulate the main point of a story, a reader may ask, “what is this story about?” It is important that this is not just a one or two word topic. Instead, a reader should include important details about who is involved and what happens. The main point or main idea is generally a one or two sentence summary.

With nonfiction, the writer often puts the main idea either in the first paragraph of an essay or in the first sentence of a paragraph. If so, this is called either a thesis statement of an essay or a topic sentence of a paragraph.

Identifying Supporting Details

Supporting details refers to the words, phrases, and statements that support, define, or explain the main idea.

While the main idea can be expressed in one or two sentences, the supporting details are more elaborate. To find the supporting details of a piece of fiction, a reader may ask the following questions: who, what, when, where, why, and how.

To find the supporting details in a piece of nonfiction, a reader should consider how the author tries to prove the main idea. Does the author use statistics or narratives or case studies to prove the main idea?

Main Idea and Supporting Details Examples

This is a non-fiction paragraph:

There are many benefits to living in the suburbs. First, suburbs are often less crowded than urban areas. Because of this, many residents can have larger yards and homes. Another benefit to living in the suburbs is that there is often a relatively short commute to the nearest major city. This allows residents to get to work in the city or experience the cultural benefits that large cities can provide. Finally, many people love to live in suburbs because they do not have the traffic congestion found in major cities. These are some of the benefits to living in a suburb.

In the above paragraph, the main idea can be found in the first sentence: There are many benefits to living in the suburbs.

The supporting details are the three points the writer includes to prove that main idea:

  1. Suburbs are less crowded than cities.
  2. Suburban residents can still experience the benefits of major cities.
  3. There is less traffic congestion in the suburbs.

Beauty and the Beast is a well-known fictional piece of writing.

The main idea of Beauty and the Beast is that a young woman is taken captive by a prince who was turned into a beast due to a curse. Because they fall in love, the curse is broken, and they live happily ever after.

A major theme of the story is that beauty cannot only be found in outward appearances.

A few supporting ideas include

  1. A curse was put on a handsome prince turning him into a beast.
  2. The beast takes a young woman captive, and she is repulsed by him at first.
  3. Slowly they begin to get to know each other, and the woman starts to fall in love with the beast.

Lesson Summary

When reading a piece of writing, either fiction or non-fiction, a writer will want to look for the main idea, theme, plot, and supporting details. The main idea, or main point, is what a piece of writing is about. It is usually stated as a one or two sentence summary. The theme is the overall message or moral of a story. The plot refers to what happens in a story. Supporting details are the words, phrases, and statements that support define, or explain the main idea. Often a writer will use supporting details to explain a main idea and demonstrate a clear understanding of that main idea.

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