as to which

USAGE SUMMARY

"as to which" is correct and is commonly used in written English.
It is used to introduce further information in a sentence (particularly when referring back to something that has previously been mentioned). For example: "The degree of success they achieved depended on many factors, as to which the professor refused to speculate."

✓ Grammatically correct

News & Media

Science

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

Take your pick as to which is an appropriate comparison.

The Guardian - Film

As to which is greater... can we give an answer?

The Guardian - Arts

As to which breed of cat Kevin will inhabit?

The Guardian - Film

As to which is which, all bets are open.

The New York Times - Arts

Some quantifiers are choosy as to which they apply to.

The Guardian - Books

No word as to which rival candidate might have intervened.

Independent

One guess as to which iteration was the more affecting.

The New York Times - Arts

Bankruptcy law is fuzzy as to which group takes priority.

The New York Times

The recount commission may make new and independent determinations as to which ballots shall be counted.

The New York Times

"There's been no decision made as to which fires they'll be assigned to".

The New York Times

By seventh grade, Gallagher said, it is "mostly clear" as to which players have football talent.

The New York Times - Sports

Expert writing Tips

Best practice

Prefer "as to which" in formal writing when you want to emphasize clarity and precision in identifying which option applies.

Common error

Avoid using "as to which" in casual conversation or informal writing. Simpler alternatives like "about which" or direct questions are often more appropriate.

Linguistic Context

The phrase "as to which" functions as a prepositional phrase introducing a dependent clause. It typically follows a statement or situation where a choice or selection must be made. The phrase serves to specify or inquire about the particular item or option being considered, as shown in Ludwig's examples.

Expression frequency: Very common

Frequent in

News & Media

80%

Science

10%

Formal & Business

5%

Less common in

Academia

2%

Encyclopedias

1%

Wiki

2%

Ludwig's WRAP-UP

"As to which" is a grammatically correct and frequently used phrase in written English, functioning as a prepositional phrase to introduce a clause that specifies or questions a selection. Ludwig shows its prevalence in News & Media and Science contexts. It's best used in formal or neutral contexts when clarity is needed. For informal situations, simpler alternatives like "about which" are preferable. While "as to which" enjoys consistent usage, understanding its appropriate context ensures effective and precise communication.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

regarding which

Replaces "as to" with "regarding", maintaining a formal tone but shifting the emphasis slightly to the subject being discussed.

as regards which

Similar to "regarding which", providing a near synonym with little difference in meaning.

concerning which

Similar to "regarding which", but may imply a stronger sense of relevance or importance.

with regard to which

A more formal equivalent of "regarding which", suitable for professional contexts.

in relation to which

More verbose, emphasizing the connection or relationship to a previously mentioned item.

with respect to which

Formal and emphasizes consideration or regard for a particular aspect.

in terms of which

Focuses on the criteria or standards used for making a selection.

on the subject of which

Introduces a specific topic for consideration.

when it comes to which

More conversational, introducing a specific aspect or consideration.

about which

Simpler and more direct, suitable for less formal contexts.

FAQs

How can I use "as to which" in a sentence?

Use "as to which" to introduce a clause that specifies or questions which of several options is being referred to. For example, "There was confusion as to which route was the fastest."

What phrases can I use instead of "as to which"?

Alternatives include "regarding which", "concerning which", or simply "about which", depending on the context and desired level of formality.

Is "as to which" formal or informal?

"As to which" leans towards formal usage. Simpler alternatives are generally preferred in informal contexts.

What is the difference between "as to which" and "regarding which"?

The phrases "as to which" and "regarding which" are largely interchangeable, with "regarding which" perhaps having a slightly broader application.