First some terminology, so that we can agree what we are talking about. I will distinguish semantic/thematic roles from grammatical functions:
- Agent=doer of the action
- Theme=directly affected/acted upon by the action
- Goal=end state/location of the Theme
- Subject=noun phrase which agrees with the verb/receives nominative case (I/he/they, etc.)
- Direct Object = noun phrase adjacent to the verb which gets a semantic role from that verb; receives accusative case (me/him/them, etc.)
- Indirect Object = noun phrase introduced by the preposition to.
A large part of the confusion in describing verbs like give in English comes from not distinguishing Goal from Indirect Object, and not distinguishing Direct Object from Theme.
Verbs like give in English have two alternate forms:
- John gave a book to me.
- John gave me a book.
Now lets apply the definitions above to these two sentences.
In both (1) and (2), John is the Agent (doer of the action), and also the Subject (agrees with the verb/would be he as a pronoun).
In (1) a book is the Theme (directly affected by the action) and also the Direct Object (adjacent to the verb and getting a semantic role from it. Me is the Goal (end state/location of the Theme) and also the Indirect Object (introduced by the preposition to).
In (2), however, things change. English has a rule commonly called "Dative Shift" which turns an Indirect Object (introduced by to) into a Direct Object (adjacent to the verb). This doesn't affect the semantic roles of the verb, but it does affect the grammatical functions. So in (2) although me is still the Goal (end state/location of the Theme) it is now the Direct Object (adjacent to the verb). A book is still the Theme (directly affected by the action) but is no longer the Direct Object. We can call it a second object if you like.
Now we can look at the Passive rule in English. Very roughly (because strictly speaking this is not quite correct), the passive in English makes the Direct Object of the active sentence the Subject of the passive sentence, and makes the subject of the active sentence an optional argument introduced by the preposition by. Since there are two active forms in (1) and (2) there should be two corresponding passive forms, and in fact, there are:
- A book was given to me (by John).
- I was given a book (by John).
In (3) the Direct Object of (1) became the subject, and in (4) the Direct Object of (2) became the subject. Since Passive doesn't care about the semantic roles, only the grammatical functions, we retain the same semantic roles as before: a book is the Theme in both sentences, and me/I is the Goal. Crucially, a book in (4) is not the direct object, but still the "second object" it was in the active form.
Now remember in (2) I said that a book is no longer the direct object of give because the Dative Shift rule makes the Indirect Object into a Direct Object. This predicts that the second object in (2) should not be able to undergo passive, because it it no longer a direct object, and this is in fact the case, as we can see in (5):
- *A book was given me.
This contrasts minimally with (3) which contains the preposition to. In that sentence, a book was the direct object in the active form, and therefore is able to be the target of the passive rule.