Object of the Preposition vs Indirect Object

Greetings.

In the statement "I gave a book to Marc."  Is "Marc" the indirect object or the object of the preposition "to"?

The question comes up because many statements involving the preposition "to" can be rewritten as follows:

I gave Marc the book.

In this sense, "Marc" appears to be the indirect object, or is it still the object of the preposition "to", though the preposition is unspoken?

Thank you

Allanya

In the statement "I gave a book to Marc."  Is "Marc" the indirect object or the object of the preposition "to"?

It depends on which grammar book you read.

Some systems say that only the version without a preposition should be called an indirect object.
In such a system, I gave a book to Marc doesn't have an indirect object; I gave Marc a book does.

Other systems say that an indirect object is present no matter how it is expressed:  a single word, an object of the preposition to, or an object of the preposition for.  (gave Marc a book; brought a book to Marc; sang a song for Marc)  In this kind of system, Marc is both an indirect object and an object of the preposition to in I gave a book to Marc.

I personally use the second system.

If you are taking a class where this distinction is important, be sure to find out from your teacher which system is being used in your class.

CJ