prevent

prevent — verb

1. to take action in order to make sure that something does not happen or that some

1.verbtransitiveB1
Definition

to take action in order to make sure that something does not happen or that someone does not do what they intended to do.

Example

Trang's quick thinking prevented a serious accident on the highway.

prevented + noun phrase (quick thinking prevented an accident)

The new building code is designed to prevent fires from spreading quickly.

passive: designed to prevent [noun] from [gerund]

Common collocations
  • prevent + accident / disease / crime / fire / war / damage / loss / injury / disaster
  • prevent + someone + from + gerund
  • prevent + effectively / entirely / completely
Synonyms
  • stop

    more general; can mean interrupt something already happening, not just act beforehand

  • avoid

    focuses on keeping away from something rather than actively blocking it

  • hinder

    more formal; suggests making something difficult rather than impossible

  • block

    more physical or concrete; often about a barrier or obstacle

Antonyms
  • allow

    to let something happen

  • cause

    to make something happen

Grammar Patterns

prevent + noun phrase

prevent + noun + from + gerund

prevent + gerund (informal)

Usage Note

Unlike stop, prevent emphasises action taken beforehand to avoid something rather than interrupting something already in progress. The structure prevent + object + from + gerund (prevent him from leaving) is standard in formal English. In informal spoken English, from may be dropped (The rain prevented us going out), but this is less common in writing.

Common Mistakes

The medicine prevented him to get sick.
The medicine prevented him from getting sick.
After prevent, use from + gerund, not to + infinitive.
We must prevent the disease.' (when you mean 'we must avoid the disease')
We must prevent the disease from spreading.
Prevent needs an object that can be stopped; use avoid when the object is something you simply stay away from.

Word family

Synonym discussion

Sense: verb/1

Prevent, stop, avoid, hinder, and block all relate to keeping things from happening, but they differ in timing and method. Prevent focuses on acting beforehand to make an event impossible — you install a fence to prevent children from falling into the pool. Stop is more general and can mean interrupting something already in motion — a lifeguard stops a swimmer who has gone too far out. Avoid means staying away from something rather than actively blocking it — you avoid the busy road by taking a side street. Hinder is more formal and suggests making progress difficult without necessarily stopping it — heavy traffic hindered the delivery driver. Block is physical or concrete, suggesting a barrier — a fallen tree blocked the road. Choose prevent when the emphasis is on advance planning; choose stop when the action interrupts a process already underway.

prevent ↗stop ↗avoid ↗hinderblock ↗

Common collocations

Nouns

  • measures
  • steps
  • ways
  • efforts
  • attempts
  • methods
  • strategy

Adverbs

Phrases

  • in order to prevent
  • help prevent
  • aim to prevent
  • designed to prevent

Prepositions

Etymology

LatinFrenchEnglish

Prevent comes from the Latin word 'praevenire', which means 'to come before' or 'to go ahead of'. It is made from 'prae-' (before) and 'venire' (to come). The word entered English through French in the 1400s. At first, it meant the same as its Latin origin — to act before or to anticipate. Over time, the meaning shifted to 'to stop something from happening', because if you act before an event, you can make sure it does not occur.