how many的用法
（1）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。例如:a.There is a book on the desk.(用how many改为特殊疑问句)
How many books are there on the desk?
b.There are seven days in a week.(对划线部分进行提问)
How many days are there in a week?
(2)记忆口诀
how many在句首,名词复数跟着走,一般问句紧相随,其它成分不要丢。