This  is  Tom's  book.
                 Is  this      Tom's  book?
　 　Whose book  Is  this?
         ↑
     これはだれの本ですか。

    　 　　　　　　      You  have  three  books.
                     Do  you  have  three  books?
　 　How many books  do  you  have?
           ↑
     あなたは何冊の本をもっていますか。


疑問詞の後ろに疑問文を作る。