know whether

USAGE SUMMARY

The phrase "know whether" is correct and usable in written English.
You would use it when you are trying to determine if something is true or false. For example: I don't know whether he will be able to make it to the meeting on time.

✓ Grammatically correct

News & Media

Science

Wiki

Human-verified examples from authoritative sources

Exact Expressions

59 human-written examples

You never know whether you offered enough".

The New York Times

How does anybody know whether I am?

Independent

I want to know whether to celebrate.

BBC

I don't know whether we'll know whether it is decisive".

The Guardian

"And he doesn't know whether he cares".

The New Yorker

Doesn't know whether to help push her.

The New Yorker

"He wants to know whether we're ready.

The New York Times

"We don't know whether they have C.T.E.

The New York Times - Sports

You don't know whether you beat Oprah?

The New York Times - Magazine

Doesn't know whether he should marry her.

The New Yorker

"I don't know whether this is coincidence.

The New York Times

Expert writing Tips

Best practice

When using "know whether", ensure that the sentence clearly presents two alternative possibilities. For example: "I don't "know whether" to laugh or cry."

Common error

Avoid placing unnecessary words between "know" and "whether". For instance, instead of "I want to know really whether", use "I want to "know whether"."

Linguistic Context

The phrase "know whether" functions as a conjunction phrase, introducing a subordinate clause that expresses doubt or inquiry about a particular situation. Ludwig AI confirms this usage through numerous examples where it introduces an alternative.

Expression frequency: Very common

Frequent in

News & Media

45%

Science

35%

Wiki

10%

Less common in

Formal & Business

5%

Reference

3%

Encyclopedias

2%

Ludwig's WRAP-UP

In summary, the phrase "know whether" is a grammatically correct and frequently used expression to indicate uncertainty or inquiry about two possibilities. As Ludwig AI points out, its primary function is to introduce a subordinate clause expressing doubt. It's versatile, appearing in various contexts from news and media to scientific literature, though it leans toward a neutral to formal register. When writing, ensure you present clear alternative possibilities when using "know whether", and be mindful of avoiding unnecessary words within the phrase.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

determine if

Focuses on the act of finding out information; it's slightly more direct.

find out if

Implies discovering something, often after some investigation.

discover if

Suggests uncovering information that was previously unknown.

ascertain whether

A more formal and precise way to express finding something out.

confirm whether

Emphasizes the need to verify or validate information.

establish if

Suggests confirming or proving something to be true.

figure out whether

Implies problem-solving to understand the situation.

investigate whether

Implies a more in-depth inquiry to determine the truth.

check to see if

Focuses on verification, often through a specific action.

be certain if

Highlights the importance of feeling certain before acting

FAQs

How to use "know whether" in a sentence?

Use "know whether" to express uncertainty or inquiry about one of two possibilities. For example: "Do you "know whether" the train is on time?"

What can I say instead of "know whether"?

You can use alternatives like "determine if", "ascertain whether", or "find out if" depending on the context.

Which is correct, "know whether" or "know if"?

While "know if" is often used in informal contexts, "know whether" is generally considered more grammatically correct, especially in formal writing. "Know whether" is also necessary when presenting two explicit alternatives.

What's the difference between "know whether" and "know that"?

"Know whether" implies uncertainty and a choice between two possibilities. "Know that", on the other hand, indicates certainty and factual knowledge.