Indirect Object Clauses and The Prep Object Clause

The italicised word in the next example represents the Indirect Object at the level of the clause:

He gave me the book.

The Indirect Object here precedes the Direct Object ('the book'). If we want it to follow the Direct Object, it gets the preposition 'to':

He gave the book to me.

Given the similarity of meaning between the two formulations , in this section both of them will be treated in the same way. According to Tamara Lacatusu in Essentials of English Syntax. Complex Structures, p. 123, on the complex sentence level the rewritings of me and to me as clauses are considered Indirect Object Clauses. She considers that there is only one possibility open here, namely embedding of Independent Relative Clauses in which the relative pronoun is preceded by the preposition 'to':

He gave the book 1/ to whoever wanted it. 2/