ACTIVE AND PASSIVE VOICE

Active Voice

In sentences written in active voice, the subject performs the action expressed in the verb; the subject acts.

Examples:

· I am playing soccer now
· We visted the museum yesterday.
· They were climbing for twenty-seven days.
· David has been working for two hours, and he hasn't finished yet.

Passive Voice

In sentences written in passive voice, the subject receives the action expressed in the verb; the subject is acted upon. The agent performing the action may appear in a "by the . . ." phrase or may be omitted.
(agent performing action has been omitted.)

Examples:

active:
· The company ships the computers to many foreign countries.
passive:
· Computers are shipped to many foreign countries.

active:
· The delivery man delivered the package yesterday.
passive:
· The package was delivered yesterday.

Also, overuse of passive voice throughout an essay can cause your prose to seem flat and uninteresting. In scientific writing, however, passive voice is more readily accepted since using it allows one to write without using personal pronouns or the names of particular researchers as the subjects of sentences (see the third example above). This practice helps to create the appearance of an objective, fact-based discourse because writers can present research and conclusions without attributing them to particular agents. Instead, the writing appears to convey information that is not limited or biased by individual perspectives or personal interests.


You can recognize passive-voice expressions because the verb phrase will always include a form of be, such as am, is, was, were, are, or been. The presence of a be-verb, however, does not necessarily mean that the sentence is in passive voice. Another way to recognize passive-voice sentences is that they may include a "by the..." phrase after the verb; the agent performing the action, if named, is the object of the preposition in this phrase.

TAKE: http://owl.english.purdue.edu/handouts/grammar/g_actpass.html