Active and Passive Voice

Active and Passive Voice

Sentences in English can be active or passive. Verbs, correspondingly, have active and passive forms. The distinction between the active and passive voices can be tricky, but it is, essentially, quite simple. In a sentence in the active voice, the subject is actively performing the action, and the object is receiving it.
For example:
The cat ate the rat.
In this sentence, the subject cat is performing the action of eating the rat.
The passive voice, on the other hand, sees a reversal of roles. For example:
The rat was eaten by the cat. Here, the rat is the subject, but it is not actively, but passively performing the action. It is allowing the action to be performed on it. It is the object, the cat, which is actually performing the action, although syntactically it is receiving it.
Most sentences are in the active voice. The passive voice is employed when the noun that generally would have been the object, needs emphasis, or when you do not want to mention or do not know the identity of the subject.

Active Voice
We've all heard this before from our English teachers: 'You should always write in the active voice.' But what exactly does this mean? Here are two different ways to construct a similar sentence.
1. Henry threw the ball.
2. The ball was thrown by Henry.

Let's take a look at the first sentence. The subject of the sentence is 'Henry,' and 'ball' is the object, which receives the action of the verb 'threw'
Now moving onto the second sentence, we can see that 'ball' is the subject of the sentence, and 'Henry' is now the object that receives the action of the verb 'was thrown'.
The grammatical term active voice refers to a sentence in which the subject performs an action indicated by the verb. The first sentence is written in active voice, because Henry is the subject and he is performing the action.
By comparison, the second sentence is written in passive voice, because Henry is no longer the subject; now, he's just the object at the end of the sentence. In grammar, the passive voice refers to sentences in which the verb acts upon a noun or subject, which receives instead of initiates the action.

Examples
Here are some more examples of sentences using the active voice:
I called Jimmy last night.
Deborah read the book.
Bobby dug the ditch.

Now, let's take a look at how those same sentences read in the passive voice:
Jimmy was called by me last night.
The book was read by Deborah.
The ditch was dug by Bobby.
Did you notice that all the sentences written in the passive voice used the verb 'to be'?

Importance of the Active Voice
Creative writing and especially business reports need to be direct and to the point. As a writer, you don't want your audience and readers to lose interest. Writing in the active voice not only helps to maintain their interest; it can also dramatically improve the quality of your work. In following one of the most basic grammar and writing principles, you want to make sure you know who is doing what in a sentence. Sentences written in the active voice have life and energy in them. They are also cleaner and less wordy. Sentences written in the passive voice often sound awkward, almost backwards and convoluted.
Go back and take a look at some of the examples of sentences written in the active and passive voice shown earlier in the lesson and read them out loud. Notice how more energetic and engaging the active voice sentences are compared to the examples written in passive voice.
Remember, it's one thing to grab your reader's attention; it's another thing to maintain the reader's focus. Writing complicated, dull, and wordy sentences in the passive voice can bore or even confuse your reading audience.

Identifying the Active Voice
When you're done with this lesson, go find a copy of a paper that you've written in the past. Read through it to see if there are any instances where you may have written in the passive voice. They're usually accompanied by two warning signs:
While not always true, often times the word 'by' indicates the passive voice, as in, 'an action was done by someone!' Whenever you spot the word 'by' in your writing, go back and double-check your sentence.
A form of the verb 'to be' typically indicates the use of the passive voice, as in 'some action was being done by someone!' Be on the lookout for all of the verb's tenses: 'am,' 'are,' 'is,' 'was,' 'were,' 'been,' and being

Passive Voice
The passive voice is used when we want to emphasize the action (the verb) and the object of a sentence rather than subject. This means that the subject is either less important than the action itself or that we don’t know who or what the subject is.
My laptop was stolen. (The object – now the subject = My laptop / action= was stolen)
Passive: Napa Valley is known for its excellent wines.
Active: [Many people] know Napa Valley for its excellent wines.
Passive: Twenty civilians were killed in the bomb explosion.
Active: Someone killed twenty civilians in the bomb explosion.

The passive agent
When we know who the subject is, we put it at the end with by. We call this an agent.

Passive: The Mona Lisa was painted by Leonardo Da Vinci. (agent =Leonardo Da Vinci )
Active: Leonaro Da Vinci painted the Mona Lisa.
Most writing instructors and editors recommend against using the passive voice, when possible. The reason for this is that when you use the active voice, your writing is clearer and less complicated.

Active: While Mr. Taylor was driving down Highway 101, a police officer pulled him over and gave him a speeding ticket.
Passive: While Mr. Taylor was driving down Highway 101, he was pulled over and given a ticket by a police officer.
If it’s a long sentence and you know who the subject is, it’s best to use the active voice.

The passive is often used to report something or to state a fact.

Highway 15 was closed yesterday due to a serious road accident.
A lot of corn is grown in Iowa.
Forming the passive voice
The passive voice is not a tense in English. Each tense has its own passive voice which is created by using a form of the auxiliary verb to be + V3 (past participle)

The passive voice in each tense:

All of the rules for passive negatives and questions are the same as for the active voice.
Note: Verbs that have no object (no one to “receive” the action) cannot be put into the passive, such as, arrive, come, die, exist, go, happen, have, live, occur sleep, etc.

Tense
Auxiliary verb + sample V3 (past participle)
Examples
Present simple
am, is, are + made
Wine is made from grapes.Many cars are made in Japan.
Present progressive
am, is, are + being + sent
The document is being sent right now.I am being sent to work in the London office.
Past simple
was, were + invited
John was invited to speak at the conference.We were invited to Daniel and Mary’s wedding.
Past progressive
was, were + being + washed
The dog was being washed when I got home.Their cars were being washed while they were in the mall shopping.
Future (will)
will be + signed
The contract will be signed tomorrow.The documents will all be signed by next week.
Future (going to)
am, is, are + going to be + built
A bridge is going to be built within the next two years.New houses are going to be built in our neighborhood.
Present perfect
has, have + been + sold
That start-up has been sold for $5 million.The rights to his book have been sold for $250,000.
Past perfect
had + been + hired
The new manager had been hired before John left the company.All the employees had hired before the store opened.
Future perfect
will + have been + finished
The car will have been loaded by the time he gets home.The crates will have been loaded by then.
Modals: can/could
can, could + be + issued
A passport can only be issued at the embassy.He said the documents could be issued within the week.
Modal: have to
have to, has to, had to + be + arranged
A babysitter has to be arranged for this evening.Joan’s travel plans have to be arranged by December.
Modal: must
must + be + stopped
Criminals must be stopped before they commit crimes.

http://www.englishleap.com/other-resources/active-passive-voice
http://www.gingersoftware.com/content/grammar-rules/verbs/passive-voice/
http://www.law.cuny.edu/legal-writing/studets/grammar/active-passive-voice.html