# based on sth

CEFR A2 · Phrasal verb

Source: https://englishreference.com/word/based-on-sth
Updated: 2026-04-24

## Definition

If something is based on an idea or fact, it uses that as its foundation or starting point.

For teachers: A transitive verb, 'to base sth on sth', meaning to use a fact, idea, or principle as the foundation upon which another thing is developed.

## Examples

- The film is based on a true story.
- The company's decision was based on extensive market research and customer feedback.
- Her entire philosophical framework is based on a radical reinterpretation of Kantian ethics, challenging long-held assumptions about moral duty.

## Pitfalls

- Not "This movie based in a true story." but "This movie is based on a true story." — The correct preposition is 'on', not 'in', and the passive form 'is based' is needed here.

## Usage notes

- Often used in the passive voice ('is based on') to describe the origin or foundation of something.
- Teaching tip: Point out the common adverbial use at the start of a sentence, e.g., 'Based on the results, we will proceed.'

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.