is not known

USAGE SUMMARY

"is not known" is a correct and usable phrase in written English.
You can use it when you are talking about something that is not known, such as a fact or information. For example, "The perpetrator of the crime is not known."

✓ Grammatically correct

News & Media

Academia

Science

Wiki

Encyclopedias

Formal & Business

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

The reason is not known.

The New York Times - Health

Precisely where is not known.

The New York Times

His condition is not known.

The New York Times

Taylor is not known.

Columbia University

Why they didn't is not known.

The New Yorker

He is not known to be married.

The New York Times

Often, the underlying reason is not known.

The New York Times - Health

The cause of death is not known.

The New York Times

The man's condition is not known.

The New York Times

Mr. Bloomberg is not known for sentimentality.

The New York Times

There is plenty that is not known.

The New York Times

Expert writing Tips

Best practice

Use "is not known" to clearly state the absence of information or understanding about a particular subject. Ensure the context makes it clear what specifically is unknown.

Common error

Ensure that when using "is not known", you clearly define what is not known. Avoid vague statements that leave the reader wondering about the subject of uncertainty.

Linguistic Context

The phrase "is not known" functions as a declarative statement indicating a lack of knowledge or certainty regarding a particular subject. As Ludwig AI confirms, it's a common way to express that information is currently unavailable.

Expression frequency: Very common

Frequent in

News & Media

37%

Academia

30%

Science

14%

Less common in

Wiki

10%

Encyclopedias

5%

Formal & Business

4%

Ludwig's WRAP-UP

The phrase "is not known" is a versatile and grammatically sound way to express a lack of knowledge or certainty. As Ludwig AI highlights, it is widely used across diverse fields like news, academia, and science. While "is not known" is generally appropriate, remember to clearly define what specifically is unknown to avoid vagueness. Consider alternatives such as "remains unknown" or "is uncertain" to add nuance. Remember that accuracy and context are the keys to impactful writing.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

remains unknown

Emphasizes the continuation of the state of being unknown.

is uncertain

Highlights the lack of certainty surrounding a piece of information.

is undetermined

Focuses on the fact that a decision or conclusion has not yet been reached.

is unconfirmed

Suggests that information is awaiting verification.

is not clear

Indicates a lack of clarity or understanding.

is obscure

Highlights the ambiguous and vague nature of the subject.

has not been established

Emphasizes the lack of proof or validation.

is still a mystery

Implies a sense of intrigue and unsolved nature.

eludes understanding

Suggests that the information is difficult to grasp or comprehend.

defies explanation

Indicates that there is no rational or logical explanation.

FAQs

How can I use "is not known" in a sentence?

Use "is not known" to indicate that information about a particular subject is currently unavailable or uncertain. For instance, "The long-term effects of the medication "are not known"."

What are some alternatives to "is not known"?

Alternatives include "remains unknown", "is uncertain", or "is undetermined". The best choice depends on the specific nuance you want to convey.

Is it better to say "is not known" or "is unknown"?

"Is not known" and "is unknown" are often interchangeable. However, "is not known" can sometimes imply a process of discovery, suggesting that the information may become available in the future. "Is unknown" simply states that the information is currently not known.

What's the difference between "is not known" and "has not been established"?

"Is not known" implies a lack of information or understanding. "Has not been established" suggests that something lacks proof or validation. For example, "The effectiveness of this treatment "is not known"" versus "The link between these two factors "has not been established"".