Sometimes the active voice is more appropriate and sometimes the passive voice is most suitable. It depends on the purpose of the writing.
@village shop: I've copied and pasted from some TA grammar training that I did to show the difference between the active and passive voice. The examples are supposed to have pictures and labels going to the different words (which made it a lot clearer), but they wouldn't copy over.
A sentence using the ACTIVE voice is one where the subject of the sentence carries out the action described by the verb and the object of the sentence has the action done to it.
Eg: "The mouse (subject) frightened (verb) the cat (object)."
A sentence using the PASSIVE verb is one where the usual order is reversed. The action done to the object of the sentence is described. If the subject is included in the sentence, it is usually at the end.
Eg: "The cat (object) was frightened (verb) by the mouse (subject)."
Sometimes, in the passive mode, the agent (subject) can be left out completely.
Eg: The cat was frightened.
Sentences with passive verbs are more often used in written than in spoken English. It sounds more formal and impersonal and so is often used in:
• reports of crimes - He was sentenced to two years in jail
• newspaper reports - The football match was cancelled.
• When it isn’t important who performed the action eg in scientific writing – The tripod was moved away from the flame.
• announcements - The 13:15 train to York has been delayed.
• notices – Customers are asked not to smoke.
• To avoid admitting responsibility – mistakes were made (companies and politicians love this - it avoids saying who made the mistake, so they don't truly admit responsibility)
• When you want to save new or important information until the end of the sentence for emphasis: The picture was painted by Constable
• When you do not know who performed the action: A valuable painting was stolen from the museum last night.