Libro

[Tomisimo]

Actually, I take back what I said above. Poli you're right.

For example, him is used both as a direct and indirect object pronoun. I was confusing it with the subject pronoun he.

I gave him the book. I gave the book to him. (him is an indirect object)
I gave him to his mother. (him is a direct object)

[Alfonso]

That's it. The systems are different. I'm not very fond of doing this kind of comparison, but just have a look at the Spanish system and you'll see it's different from the English one.