English Reference
verb

inform

v.
US /ˌɪnˈfɔɹm/ UK /ɪnfˈɔːm/ in·form UK spelling informs

  1. 01 B2 Upper Intermediate

    to give someone information or tell them about a fact.

    to impart knowledge or communicate specific facts to a person. Transitive — requires a direct object, often followed by 'of' or a 'that' clause.

    Simple

    Please inform the office if your contact details change during the year.

    In context

    The company failed to inform its shareholders of the potential risks before the merger was finalised.

    Pitfall
    I informed him the news. I informed him of the news.

    When you tell someone about a specific topic using 'inform', you must use the preposition 'of'.

  2. 02 C1 Advanced AcademicFormal

    to be the main idea or feeling that influences how something is made or done.

    to imbue with a quality or to be the characterising force behind an action, theory, or creative work.

    Simple

    Her research on climate change helped inform the government's new laws.

    In context

    A deep sense of social justice informs every chapter of the author's latest novel, providing a moral framework for the characters' choices.

  3. 03 C1 Advanced Formal Law

    to give information to the police or authorities about someone who has done something wrong.

    to provide incriminating information about a person to the authorities. Intransitive — typically used with the preposition 'on'.

    Simple

    He was afraid that his business partner might inform on him to the police.

    In context

    The witness was reluctant to inform on his associates, fearing retaliation from the criminal organisation.

    Usage

    Usually takes the preposition 'on' followed by the person being reported.

Usage inform future · fully inform · inform design

The score should inform your decision – not make it.

The Conversation· 18 Aug 2026

Other banks may inform their EU-based clients that they cannot keep their account open.

The Local· 18 Aug 2026

Etymology 1

From Middle English informen, enformen, borrowed from Old French enformer, informer (“to train, instruct, inform”), from Latin īnfōrmō (“to shape, form, train, instruct, educate”), from in- (“into”) + fōrma (“form, shape”), equivalent to in- + form.

Etymology 2

From Latin īnfōrmis.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin īnfōrmō
Level B2 · Upper Intermediate
Frequency Common
Updated