N as to wh
Nouns with other meanings
There are a number of other nouns which have this pattern. They are all abstract nouns.
He offered no clue as to who he wants to see fill the newly created post of vice-president.
Eventually, the black box of the plane was found, but it provided no concrete evidence as to what happened.
There is no mystery as to why this has happened.
He set out a number of options as to how we might proceed.
The UN official says so far there's no proof as to who's responsible.
We have never been given any reason as to why the children were not placed into our care.
In the case of choice, clue, dilemma, option, and quandary, the preposition as to is occasionally followed by a wh-word and a to-infinitive clause. This pattern is N as to wh-to-inf.
Turku is Finland's oldest town and offers plenty of choice as to where to eat.
With most nouns in this group, the preposition as to is occasionally followed by a noun group.
ambiguity choice clue criterion dilemma evidence guide issue mystery option proof quandary question question mark reason signals
Meanwhile, there were conflicting signals as to the health of the ongoing peace talks.