how many book后面跟单数还是复数

how many books 有多少书

how many后面的名词及谓语动词都要用复数，它是修饰可数名词的。句式是:How many+复数名词+一般疑问句+?

How many 表示多少，用来问数量。

如，

How many books are there on the desk

有多少本书在桌子上?

How many days are there in a week

一周有多少天?。