There are many books in the bag.变成一般疑问句又有了，There are four birds in the tree.用How many提问They are going to have a party next Sunday.用What提问Mike is cleaning the window.对cleaning the window 提问Jack enjoys listening to music.改为一般疑问句

Is there many books in the bag?
一般疑问句
how many 提问：how many birds are there in the tree?
what提问。what are they going to do next sunday?
cleaning the window提问：what is Mike doing?
一般疑问句：Does Jack enjoy listening to music?

Are there many books in the bag?
How many birds are there in the tree?
What are they going to have next Sunday?
What is Mike doing?
Does Jack enjoy listening to music?

有三种答案
如果是一般情况可以用
Are there any （any 可省略）books in the bag?
如果针对“书包里有许多书吗”提问,则是
Are there many books in the bag?
补充答案
How many birds are there in the tree?
What are they going to have next Sunday?
What is Mike doing?
Does Jack enjoy listening to music?

Are there any books in the bag?