Most verbs can be followed by object + infinitive. Most of these structures can be made passive.

• I told them to behave. (active)
• They were told to behave. (passive)
• I asked him to send me a letter. (active)
• He was asked to send me a letter. (passive)
• They thought him to be a traitor. (active)
• He was thought to be a traitor. (passive)
• 
  

Note

All active verbs cannot be followed by object + infinitive. The verb say is one of them. With say the infinitive structure is only possible in the passive.

• Their marriage is said to be in trouble. (BUT NOT People say their marriage to be in trouble.)