Informant vs Source vs Whistleblower

When to use each in English, with meaning, register, and examples.

Informant

Beyond 10,000 (less common)

Source

Top 1,000 (very common)A2noun

Whistleblower

FormalBeyond 10,000 (less common)
Most formal: WhistleblowerMost common: Source
 InformantSourceWhistleblower
Pronunciation🇬🇧 //ɪnˈfɔːmənt//🇺🇸 //ɪnˈfɔrmənt//🇬🇧 //sɔːs//🇺🇸 //sɔrs//🇬🇧 //ˈwɪs.əlˌbloʊ.ər//🇺🇸 //ˈwɪs.əlˌbloʊ.ɚ//
MeaningA person who gives information, especially to the police.The place where something comes from.A person who reports wrongdoing or illegal activity in an organization.
ExampleThe police relied on an informant to gather crucial evidence.The source of the river is located in the mountains.The whistleblower revealed shocking information about the company's misconduct.
RegisterNeutralNeutralFormal
How commonBeyond 10,000 (less common)Top 1,000 (very common)Beyond 10,000 (less common)
CEFR level-A2-
Part of speechnoun
Collocationspolice informant, anonymous informant, key informant, confidential informant, informant agreementsource of information, primary source, data sourcelegal protection for whistleblowers, whistleblower complaints, famous whistleblower cases
Antonyms-destination, result-
Common mistakesConfused with 'informational' which refers to information-related., Using 'informant' to describe someone giving general information, not just in legal contexts.Confused with 'resource' which refers to a supply or support., Used incorrectly as a verb; 'source' is only a noun in this context.Confused with 'informant' which implies a different legal context., Misused in informal contexts where it sounds out of place.
Usage notesCommonly used in legal and police contexts. Be careful using it informally, as it can imply secrecy or betrayal.Used in both formal and informal contexts; can refer to information, origins, or places.Typically used in legal or corporate contexts. May not be appropriate in casual conversations.

Frequently asked questions: Informant vs Source vs Whistleblower

What's the difference between Informant, Source, and Whistleblower?

Informant: A person who gives information, especially to the police. Source: The place where something comes from. Whistleblower: A person who reports wrongdoing or illegal activity in an organization.

Which is more formal: Informant, Source, and Whistleblower?

Whistleblower is the most formal of these.

Which is more common: Informant, Source, and Whistleblower?

Source is the most common in everyday English.

Can you show an example of each?

Informant: The police relied on an informant to gather crucial evidence. Source: The source of the river is located in the mountains. Whistleblower: The whistleblower revealed shocking information about the company's misconduct.

Can I use Informant, Source, and Whistleblower interchangeably?

Not always. Informant, Source, and Whistleblower are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.