# basing

/ˈbeɪsɪŋ/ (US) · /bˈeɪsɪŋ/ (UK) · CEFR B1 · Verb

Source: https://englishreference.com/word/basing
Updated: 2026-05-07

## Definition

to use something as the main idea or starting point for a new thing. You use this when you build a story, a plan, or an opinion on a specific fact.

For teachers: the present participle of 'base'; refers to the act of using a particular fact, situation, or place as the foundation for something else. Often used in the passive voice followed by 'on' or 'upon'.

## Examples

- I am basing my report on the latest sales figures.
- The director is basing the movie's plot on a true story from the nineteenth century.
- By basing their entire economic strategy on a single volatile commodity, the government left the nation vulnerable to sudden shifts in global market demand.

## Pitfalls

- Not "basing in a true story" but "basing on a true story" — When 'base' means to use something as a foundation for an idea, it requires the preposition 'on', not 'in'.

## Usage notes

- Typically followed by the preposition 'on' or 'upon'.

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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.