Some sentences have infinitives or clauses as their objects. Structures like these cannot be made passive. Study the following sentences.

I hoped to marry her. (BUT NOT To marry her was hoped by me.)

I wanted to win the first prize. (NOT To win the first prize was wanted by me.)

She expected to fail. (NOT To fail was expected by her.)

I asked to go home. (NOT To go home was asked by me.)

We all thought that she was honest. (NOT That she was honest was thought by us all.)

We felt that she was the right woman for the job. (NOT That she was the right woman for the job was felt by us.)

The newspapers say that the economy is in trouble. (NOT That the economy is in trouble is said by the newspapers.)

However, it can be used as a preparatory subject for a clause. In this case, passive structures are possible.

It was thought that she was honest.

It was felt that she was the right woman for the job.

It is said that the economy is in trouble.