ENGLISH
REFERENCE

inform

v.
US //ˌɪnˈfɔɹm// UK //ɪnfˈɔːm// in·form
  1. 1 to tell or notify (v.)
    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.

    Example

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

    Example

    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. 2 to influence or shape (v.)
    C1 Advanced Academic Formal

    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.

    Example

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

    Example

    A deep sense of social justice informs every chapter of the author's latest novel, providing a moral framework for the characters' choices.
Show 1 more senseShow fewer
  1. 3 to report to authorities (v.)
    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'.

    Example

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

    Example

    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.
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.

Word family

© 2026 English Reference