# blow up

CEFR A2 · Phrasal verb

Source: https://englishreference.com/word/blow-up
Updated: 2026-04-24

## Definition

to explode or to destroy something with an explosion; it can also mean to fill something with air, like a balloon.

For teachers: to undergo or cause to undergo a sudden, violent expansion or destruction; also used transitively to denote the inflation of an object.

## Examples

- The soldiers had to blow up the old bridge.
- We need to blow up fifty balloons before the birthday party starts at noon.
- The structural integrity of the building was so compromised that the demolition crew decided to blow up the entire north wing.

## Pitfalls

- Not "He blew the balloon up it." but "He blew the balloon up." — if using a pronoun as the object, it must go between the verb and the particle.

## Usage notes

- when it means to inflate, it is usually transitive; when it means to explode, it can be transitive or intransitive.
- Teaching tip: mention the informal figurative sense 'to get very angry' (e.g., 'he blew up at me') to show how the idea of an explosion applies to emotions.

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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.