In general, a passive construction is created when the object of an active
construction becomes the subject of the passive verb. What was the subject
of the active verb (if mentioned) is now linked to the passive verb by a
preposition (commonly ‘by’ in English and porin Spanish):
Active Passive
Subject Verb Object Subject Verb ‘by’
Mary wrote the book The book was by Mary
written
Everyone loves John John is loved by everyone
(no subject) posted the letters The letters have been (no ‘by’
posted phrase)
Although passive constructions such as those above can readily be trans-
posed into Spanish, in practice Spanish frequently replaces passives with
alternatives, see 15.2.
Serand estarwith the past participle
In order to understand the passive in Spanish, it is essential to be able to
distinguish between the use of estar andserwith the past participle.
15.1