[A] «People consider/know/think» etc. «that he is …» > «It is considered/known/thought» etc. «that he is …» // «He is considered/known/thought» etc. «to be …» ; «People said that he was jealous of her» > «It was said that he was,» o bien: «He was said to be jealous of her» ; «He is thought to have information which will be useful to the police» ; «People believed that he was» > «It was believed that he was,» o bien: «He was believed to be …» ; «People know that he was» > «It is known that he was,» o bien: «He is known to have been …» [B] «You are supposed to know how to drive» = «It is your duty to know/You should know how to drive» ; «You are supposed to have finished» = «You should have finished,» pero: «He is supposed to have escaped disguised as a woman» = «People suppose that he escaped etc.» [C] Activa: We saw them go out > Pasiva: They were seen to go out ; He made us work > We were made to work ; Activa: They let us go > Pasiva: We were let go ; [D] He is believed/known/said/supposed/thought to be living abroad = People believe/know/say/suppose/think that he is living abroad ; You are supposed to be working = You should be working ; He is believed to have been waiting for a message = People believed that he was waiting for a message ; You are supposed to have been working = You should have been working.
[[A] Las oraciones con acknowledge, assume, believe, claim, consider, estimate, feel, find, know, presume, report, say, think, understand etc. tienen dos formas pasivas posibles. La construcción de infinitivo es la más clara de las dos. Se usa principalmente con to be pero a veces pueden usarse también otros infinitivos. Cuando el pensamiento concierne a una acción previa usamos el infinitivo de perfecto. Esta construcción puede usarse con el infinitivo de perfecto de cualquier verbo. [B] suppose en la pasiva puede ir seguido por el infinitivo de presente de cualquier verbo pero esta construcción usualmente traslada una idea de deber y no es por tanto el equivalente normal de suppose en la voz activa; suppose en la pasiva puede similarmente ir seguido por el infinitivo de perfecto de cualquier verbo. Esta construcción puede trasladar una idea de deber pero muy a menudo no traslada esta idea. [C] Los infinitivos colocados después de verbos pasivos son normalmente infinitivos plenos, infinitivos con «to«; let, sin embargo, se usa sin to. [D] El infinitivo continuo puede usarse después de la pasiva de believe, know, report, say, suppose, think, understand. La forma de perfecto del infinitivo continuo es también posible.]
A Practical English Grammar (A.J. Thomson & A.V. Martinet) 