warn

/wɔːrn/
verb★Beginner
formalinformal

To inform someone of a possible danger, problem, or difficulty in advance, often to prevent harm or prepare them.

The weather service warned residents of an approaching storm.

The doctor warned her about the risks of smoking.

💡

Can be used in both formal and informal contexts, but may sound more urgent or serious in formal settings.

Collocations

warn aboutTo inform someone of a specific danger or issue.warn againstTo advise someone to avoid something dangerous or harmful.warn ofTo alert someone to the possibility of something negative happening.

Synonyms

Antonyms

Related Phrases

a word of warningphrase
A piece of advice or caution given to someone.
warn someone offphrasal verb
To discourage someone from doing something or approaching someone.

💡Pro Tip

Preposition Choice

Use 'warn about' for general issues, 'warn against' for specific actions to avoid, and 'warn of' for potential dangers.

⚡Gold Rule

Formal vs. Informal

In formal contexts, 'warn' can be used to convey serious or official caution, while in informal contexts, it may be softer or more conversational.

📖Word Origin

From Middle English *warnen*, from Old English *warnian*, meaning 'to take heed, guard, or give notice.' Related to Old High German *warnōn* and Old Norse *varna*.

📝Usage Notes

The verb 'warn' is often followed by prepositions like 'about,' 'against,' or 'of' to specify what the warning is concerning. It can also be used intransitively in some contexts.

Word Breakdown

warn
To give advance notice of danger or trouble.
root
English Dictionary