- AS TO WHY -

Using just why does not sound right to me.

You could say, "Scientists are puzzled about why the pyriamids were built."

But, "as to why" is perfectly correct, although I can see why it would sound strange to a non native speaker.

sam1947I can see why it would sound strange to a non native speaker.

It sounds awful to a native too.

Chloeedoes the sentence keep its meaning if I write only 'why' instead 'as to why'?

No. You can't leave out "as to" in those sentences. "are puzzled why" and "I'm baffled why" won't work. Instead of "as to" you can have "about the reason", however, giving "are puzzled about the reason why" and "I'm baffled about the reason why"

CJ

Is the expression as to why a conjuction and is it appropriate to use it with other verb different in its meaning than it is puzzled, for example - We were talking as to why the pyramids were built. ?
Thanks a lot.

It's not appropriate with talking. There you need talking about why ...

It seems to me that as to is only used with adjectives like puzzled, but maybe someone else can come up with other examples.

CJ

One could say, "There is debate as to why the Tea Party has emerged as such a strong contender against conventional candidates in these elections."

Thanks Sam!