7,Does Tom's mother have to make him tidy his room?
（被动语态）
答：Is Tom had to make to tidy his room by his mother?
Does Tom have to be made to tidy his room by his mother？
第一 句哪里错了？为什么不能用IS，被动语态不是BE+过去分词吗？遇到要改为被动语态的问句应该怎么改（能列出一条规律吗）

情态动词 除ought 和have 外，后面只能接不带to 的不定式。也就是说表示必须，不得不have to，在这里是情态动词。have to 的被动语态的变化应该和can,must等情态动词的变化一样。

情态动词的被动语态是：情态动词+be+（及物动词的）过去分词 构成。
例如： I must finish the work before I leave.
我走之前一定要把这件工作做完。
变被动：The work must be finished before I leave.

那么如果把must替换成have to.意思相同。
I have to finish the work before I leave.
变被动：The work have to be finished before I leave.

所以be要放在have to后面。

这句是对的： 2, Does Tom have to be made to tidy his room by his mother？
have to没办法提到主语前提问，只能用助动词来提问。

另外补充：当have作为实义动词时（也就是完全动词），没有被动形式。
例如： I had a terrible dream last night.
咋晚我做了一个恶梦。
这个had就不能有被动。