Who knows how

USAGE SUMMARY

The phrase "Who knows how" is correct and usable in written English. You can use it when expressing uncertainty or when referring to a lack of knowledge about a method or process. Example: "Who knows how we ended up in this situation?" Alternative expressions include "Who can say how" and "Who understands how."

✓ Grammatically correct

News & Media

Academia

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

Who knows how Howe truly felt?

The Guardian - Lifestyle

"Who knows how many?

The New York Times

"Who knows how we'd behave?

Independent

Who knows how long?

The Guardian

Who knows how important it is?

The New York Times

Who knows how many countries are involved.

The New Yorker

Who knows how the kid is?

The New Yorker

Who knows how it all began?

Independent

Who knows how long I have?

The New York Times

Who knows how long it was there?

The New York Times - Magazine

Who knows how much either has left?

The New York Times - Sports

Expert writing Tips

Best practice

Use "Who knows how" to introduce a sense of mystery or uncertainty about a future event or a complex process.

Common error

While acceptable in general usage, excessive use of "Who knows how" can make formal writing sound speculative or lacking in authority. Opt for more precise language when possible.

Linguistic Context

The phrase "Who knows how" functions as an interrogative expression, typically used rhetorically to indicate uncertainty or to suggest that a particular outcome or method is unknowable. As noted by Ludwig, it's a grammatically correct phrase.

Expression frequency: Very common

Frequent in

News & Media

75%

Academia

15%

Formal & Business

5%

Less common in

Science

2%

Encyclopedias

1%

Wiki

2%

Ludwig's WRAP-UP

In summary, "Who knows how" is a grammatically sound and commonly used interrogative phrase to express uncertainty or a lack of knowledge. As validated by Ludwig, it is appropriate across various contexts, but its informality should be considered in professional settings. Alternatives, such as "who can tell how" or "it's anyone's guess how", may offer a more nuanced or formal tone depending on the intended audience and purpose. Remember to consider the potential for overuse and explore more precise phrasing when applicable to maintain clarity and authority in writing.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

Who can tell how

Replaces "knows" with "can tell", softening the question slightly.

Who is to know how

Adds a layer of inevitability or fate to the uncertainty.

It's anyone's guess how

Shifts the focus to the speculative nature of the outcome.

There's no telling how

Emphasizes the impossibility of predicting the outcome.

How could anyone know

Highlights the difficulty in obtaining the knowledge.

Is there any way to know how

Suggests a possible, though unlikely, method of finding out.

What are the chances of knowing how

Questions the probability of obtaining knowledge.

Who could possibly know how

Expresses incredulity about the possibility of knowing.

It remains a mystery how

Presents the lack of knowledge as an unsolved puzzle.

No one seems to know how

Highlights the widespread lack of knowledge.

FAQs

How can I use "Who knows how" in a sentence?

You can use "Who knows how" to express uncertainty about a future outcome, as in, "Who knows how this will turn out?" or to highlight the complexity of a situation where the method is unknown, such as, "Who knows how this machine works?"

What's a more formal way to say "Who knows how"?

In more formal contexts, consider alternatives like "It is difficult to predict how", "The method by which remains uncertain", or "It is not currently known how" depending on the specific meaning you wish to convey.

What can I say instead of "Who knows how" to express uncertainty?

Alternatives to express uncertainty include phrases like "who can tell how", "it's anyone's guess how", or "there's no telling how".

Is "Who knows how" grammatically correct?

Yes, "Who knows how" is grammatically correct. It follows standard English sentence structure for forming a question, using "who" as the subject and "knows how" as the verb phrase.