English Reference
Noun

investigation

n. C / U
B2 Upper Intermediate Oxford US /ˌɪnˌvɛstəˈɡeɪʃən/ UK /ɪnvˌɛstɪɡˈeɪʃən/ in·ves·ti·ga·tion UK spelling investigations

n.a careful and detailed search for facts or the truth about something. You use this when the police, a scientist, or a reporter looks into a problem to find out what happened.

n.a formal or systematic examination or research into a subject or incident. Often implies a search for evidence or the cause of a specific event.


SIMPLE

The police started an investigation into the robbery.

CONTEXTUAL

The fire department launched a full investigation to determine if the blaze was started by faulty wiring.

COMPLEX

Following the whistle-blower's testimony, the committee initiated a thorough investigation into the company's financial records to uncover any evidence of systemic fraud.

Usage

Often takes the preposition 'into' to specify the subject being examined.

Pitfall
an investigation about the crimean investigation into the crime

While 'about' is sometimes used, 'into' is the standard and more precise preposition for a formal examination.

Usage investigation into an alleged · investigation into the incident · investigation found

An investigation into the child’s death was launched and Gartshore, from Aberdeen, was arrested and charged in November 2023.

BreakingNews.ie· 14 Aug 2026

The circumstances of the incident are under investigation.

BBC News· 13 Aug 2026

Common in health writing


From Middle English investigacioun, from Old French investigacion, from Latin investigatio. Morphologically investigate + -ion.

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

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