1) Thousands of people have to build that castle for him for years

=> That castle................has to be built for him by thousands of people for years.................

2) She has never read this book before.

=> It is......................the first time she has read this book.....................

3) He failed in the examination last year

=> He did not.................pass in the examination last year....................

4)I haven't eaten this kind of food before

=> This is the first...............time I have eaten this kind of food...................