对there be句型中主语的数量如:some, five, only one等提问时,如果主语是可数名词,不管主语是单数还是复数一般都用复数形式提问。
因为问话人不知道具体的数量是多少,而且many只能接可数名词复数形式,所以be一定要用are.即用How many+可数名词复数+are there+地点/时间状语的句型结构。
例句:
1、There is a book on the desk. (用how many改为特殊疑句)How many books are there on the desk 翻译：有多少本书在桌子上?
2、There are seven days in a week. (对划线部分进行提问)How many days are there in a week 翻译：一周有多少天?