how did they know

USAGE SUMMARY

The phrase 'how did they know' is correct and usable in written English.
You can use this phrase when you are asking how someone has come into knowledge of something. For example: "The police had all the details of the crime, how did they know?".

✓ Grammatically correct

News & Media

Human-verified examples from authoritative sources

Exact Expressions

53 human-written examples

How did they know?

Forbes

How did they know his name?

The New Yorker

How did they know what was happening?

Independent

But how did they know?

The Guardian

"How did they know?" she asked.

The New York Times

HOW did they know it was the same cat?

The New York Times

Human-verified similar examples from authoritative sources

Similar Expressions

6 human-written examples

How do they know that?

The Economist

How do they know this?

The New York Times

"How do they know we're losing?

The New York Times

"But how do they know the song?

The New Yorker

How do they know what will sell?

The New Yorker

Expert writing Tips

Best practice

Vary your phrasing to avoid repetition. Consider alternatives like "what was their source?" or "how were they informed?" depending on the nuance you want to convey.

Common error

Avoid using "how did they know" when you actually mean "how did they act on that knowledge?" Knowing something and acting upon it are distinct concepts.

Linguistic Context

The phrase "how did they know" functions as an interrogative clause, typically embedded within a larger sentence or used as a direct question. It seeks to understand the origin or source of someone's knowledge. Ludwig's AI confirms its grammatical correctness.

Expression frequency: Very common

Frequent in

News & Media

85%

Formal & Business

5%

Science

5%

Less common in

Academia

2%

Encyclopedias

1%

Wiki

2%

Ludwig's WRAP-UP

The phrase "how did they know" is a common and grammatically correct way to inquire about the origin of someone's knowledge. As Ludwig AI confirms, it functions as an interrogative clause seeking to uncover the source of information. Examples show its frequent use in news and media, reflecting its role in questioning the basis of reported facts. While the phrase maintains a neutral tone suitable for various contexts, it's crucial to ensure clarity regarding who "they" refers to. Consider alternatives like "what was their source?" for stylistic variation. A common pitfall is confusing knowing with acting upon knowledge. In conclusion, "how did they know" is a versatile and essential tool for investigating the foundations of information.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

How were they aware?

Focuses on the state of being informed rather than the process of gaining knowledge.

What made them realize?

Emphasizes the realization or understanding of something.

What was their source of information?

Directly asks about the origin of the information they possessed.

How did they come to understand?

Highlights the process of comprehension.

By what means did they learn?

Focuses on the method used to acquire the information.

How did they figure it out?

Implies a process of deduction or problem-solving.

Where did they get the information?

Asks directly about the location or source of the information.

What alerted them to the fact?

Emphasizes the signal or event that brought the information to their attention.

What tipped them off?

Suggests that they received a subtle clue or hint.

How did they get wind of it?

Implies that they heard about it through rumors or informal channels.

FAQs

How can I use "how did they know" in a sentence?

Use "how did they know" when you're questioning the source or method by which someone obtained specific information. For example, "The news reported the details accurately, but "how did they know" the suspect's name before the police released it?"

What's a more formal way to ask "how did they know"?

In formal contexts, consider using phrases like "what was their source of information?", "by what means did they ascertain this?", or "how did they come to possess this knowledge?"

Is "how did they knew" grammatically correct?

No, "how did they knew" is grammatically incorrect. The correct form is ""how did they know"". The auxiliary verb "did" requires the base form of the verb "know".

What's the difference between "how did they know" and "why did they know"?

"How did they know" questions the method or source of knowledge, while "why did they know" questions the reason or motivation for possessing that knowledge. They address different aspects of the information.