ENGLISH
REFERENCE

as to whether

prep. phr..
C1 Advanced Oxford

prep. phr.. you use this to introduce a question or a choice between two possibilities, especially when there is some doubt.

prep. phr.. a complex prepositional phrase used to introduce an indirect question or a clausal complement involving alternative possibilities.


SIMPLE

There is some doubt as to whether he will arrive on time.

CONTEXTUAL

The committee has not yet made a final decision as to whether the project should continue.

COMPLEX

Legal scholars remain divided as to whether the newly proposed legislation aligns with the constitutional protections currently in place.

Usage

typically follows nouns like 'doubt', 'question', or 'decision' to introduce a specific topic of uncertainty.

Teaching tip

explain that 'as to' can often be deleted without changing the meaning, but its inclusion adds a formal, precise tone to the sentence.

Pitfall

The question as to if he will come.The question as to whether he will come.while 'if' and 'whether' are often interchangeable, 'whether' is the standard choice following the prepositional phrase 'as to'.

© 2026 English Reference