Writing Strong Supporting Details

There’s a reason the film industry acknowledges great supporting actresses and actors, and not just the stars of the show. Without the supporting cast, the film wouldn’t be possible. Instead, it would be flat, filled with plot holes, and missing dialogue that advances the script. A composition is a lot like a film: It has a clear beginning, middle, and end and tells a story about the main character or a specific topic. Like a film, written compositions need support. These are called supporting details.

What are supporting details?

Supporting details are facts, examples, definitions or descriptions that back up a claim that’s typically made in the topic sentence. They’re arguably one of the most critical components of any composition, expanding on a writer’s point-of-view while also providing structure to the work. Supporting details don’t have to be objective facts or statistics. Quotes from respected or relevant sources or personal experiences can be just as effective when used appropriately.

Supporting details play a part in spoken communication, and are even used when sharing a simple opinion. For example, when you’re trying to let a friend know that the restaurant you visited is the best restaurant you’ve ever been to, you don’t just “leave it at that.” Maybe you mention objective details, like the fact that the chef has worked at world-renowned establishments, or that she’s been awarded a Michelin Star. You could also quote a reputable food critic, or share something from your own experience.

Creating essential supporting details

Let’s see what supporting details look like in practice, using the sample paragraphs below.


Homeowners can save money by switching to a renewable energy source. According to the 2017 [Example Study], an average family in the U.S. saves over [$X] annually by switching from non-renewable energy sources to solar panels. Savings can vary by state, but one thing is clear: nearly [X%] of the homeowners surveyed reported a smaller monthly energy bill.

Renewable energy sources can also help eco-conscious families reduce their carbon footprint. “We’re always trying to find ways to protect our planet. Switching to a renewable energy source is the most significant change we’ve ever made,” said homeowner Jane Doe, who switched to solar panels in 2014. Switching to solar panels can reduce the average family’s carbon footprint by up to [X%], according to [Example Newspaper].


The main idea of the first paragraph is “homeowners can save money by switching to a renewable energy source.” This idea is backed up by supporting details: the figures from the Example Study (“saves over $X…,”, and “X% of participants…”). The source has been cited, so the audience can confirm the information.

The main idea of the second paragraph is “Renewable energy sources can also help eco-conscious families reduce their carbon footprint.” The first supporting detail is a testimonial. Jane Doe’s opinion supports the writer’s point-of-view, while providing a welcome break from facts and figures. The following sentence further supports the main idea with a concrete, objective statistics.

Supporting Details Checklist

Your composition should include:

  • Supporting details that are relevant to your main idea.
  • Reliable sources that are appropriately cited.
  • At least two supporting details per main idea.
  • More than one kind of supporting detail: facts, statistics, testimonials, examples.

Use Cite This For Me citing resources to help ensure your supporting details are cited appropriately. Check out our Harvard referencing guide, forms for MLA citations, an APA citation generator, and other citing help.