Passive with ser

It is built the way English builds its passive: ser in whatever tense is wanted, plus the participle. One thing is different at once. The English participle never changes shape, and the Spanish one agrees: La casa fue construida, Los libros fueron publicados — gender and number both.

The doer goes in with por: La novela fue escrita por Cervantes. That is the one advantage this form has over the se-passive, since only here can it be said who did it. English «by» has two Spanish translations and this is not the ambiguous one — de would be «of».

One English passive has no Spanish counterpart of any shape. «He was laughed at», «the bed had been slept in», «she was spoken to» promote the object of a preposition to subject, and Spanish cannot do it: only a direct object may become the subject of a passive. Se rieron de él — active, with nobody named — is the sentence.