This is by no means an extremely accurate rendering of Passive Voice in English, but I did manage to put together information, examples and tips from various sources which I hope may be useful for anyone trying to understand this grammar point.
18. Which object to transform into a subject depends on what you want to put the focus on. For drilling purposes, it is customary to use the first one:
25. I was shown her new house. (Note the Spanish “Me enseñósunueva casa.”)
26. Leaving aside focus or learning issues, in English the active Oi is usually preferred as the subject of the passive sentence (except with explain and suggest):
47. Have/get+ something + done (los verbos causativos) Have/ get+ object + past participle - used to talk about arranging things to be done by other people. Passive meaning - the object receives the action expressed by the past participle. Typical of an informal, spoken English. This is especially so in the case of get. I had / got my bedroom painted. (Note the Spanish “Pinté / Me pintaron el dormitorio.”) I’m going to have / get my hair cut next week. (Note the Spanish “Voy a cortarme el pelo la semanaqueviene.”) [Somebody else will do it, not me.] I must have / get my watch repaired. (Spanish “Tengoquearreglar mi reloj.”)
48. Verb + preposition We must include the preposition in the passive clause: They will send for you when the boss arrives. You will be sent for when the boss arrives. He threw away the glass bottles into the container. The glass bottles were thrown away into the container.
49. Personal and Impersonal Passive Personal Passive - the O of the active s. becomes the S of the passive s. Transitive verbscan form personal passives. They build houses. – Houses are built. Intransitive verbs normally cannot form a personal passive. If you want to, you must use an impersonal construction, Impersonal Passive. he says – it is said Impersonal Passive is not as common in English as in some other languages (e.g. German, Latin). Impersonal Passiveonly with verbs of perception(e.g. say, think, know). They say that women live longer than men. – It is said that women live longer than men.
50. Personal and Impersonal Passive Although Impersonal Passive is possible here, Personal Passive is more common. They say that women live longer than men. – Womenare said to live longer than men. The subject of the subordinate clause (women) goes to the beginning of the sentence; the verb of perception is put into passive voice. The rest of the sentence is added using an infinitive construction with to (certain auxiliary verbs and that are dropped). Sometimes the term Personal Passive is used in English lessons if the indirect object of an active sentence is to become the subject of the passive sentence.