how many

[azz]

Can one use

a. The library has how many books?

instead of

b. How many books does the library have?
?

I was taught to use (b) and that's the one I use, but I think (a) might work in informal English.

Many thanks.

[Phil White]

Not really. They are different in that the attributive use is limited to a couple of scenarios and carries a certain nuance.

"The school library has 320,000 books."
"The library has how many books?"
"I'm sorry, that should have been 32,000 books."

In the above example, the "how many" is very heavily stressed and indicates incredulity. It is difficult to make this work in a written text, but it is not uncommon in speech.

"There's about 200,000 books in storage, and then there's the books in the library itself.."
"And the library has how many books?"

This is not uncommon when enumerating the number of items in various locations or scenarios, and when further clarification is needed of one number. It will typically be heard in scenarios like committee meetings:

"Printing the leaflets will cost around £900, and then there is the cost of having them delivered."
"And that will be how much?"

The implication is that the speaker will be writing down the answer to complete their list of figures.

But you cannot simply use this construction to replace the normal question form in the case of a neutral question.

[azz]

Thank you so much!

Such a clear, precise and complete reply! Wonderful! I really appreciate it!

Many thanks.