To form the passive, use a form of the verb "be" followed by a past participle verb form. You can form the passive in several verb tenses, but the simple present and simple past are the most common.

Only transitive verbs can be passive. Intransitive verbs, or verbs that cannot take a direct object, cannot be passive. You cannot say "I was arrived by train" because the intransitive verb arrive cannot be followed by an object.

Most of the time, users should avoid the passive voice. The passive voice can make the speaker or writer seem indirect and weak. Which would you rather hear: "I love you" (active voice) or "You are loved by me" (passive voice)?

But there are several situations when you should use the passive.

The most common reason to use the passive is when the actor is unknown or unimportant. For example, "My visa was processed," and "My shoes were made in India" and "The car was imported from Germany." In these examples, it is not necessary to know exactly who performed the action.

Sometimes speakers use the passive even when they know the person who did the action. In this case, use the word by followed by the actor.

For example, "Great Expectations was written by Charles Dickens." You could also use the active voice: "Charles Dickens wrote Great Expectations." Both are correct. The passive voice emphasizes the book; the active voice emphasizes the writer.

In informal speech, the verb "be" can be replaced with the verb "get." For example, instead of saying "I was hit by a car," you can say, "I got hit by a car." Listen to this famous song by the Eurythmics. You will hear two active and two passive sentences.

Some of them want to use you
Some of them want to get used by you
Some of them want to abuse you
Some of them want to be abused

Notice how singer Annie Lennox used the passive with both "get" and "be."

Another reason to use the passive is to avoid naming the person who performed an action. This is common in politics and law.

At times, powerful people want to admit to a mistake without blaming specific people. In this case, they often use the passive phrase "mistakes were made." Listen to a TV interview with President Obama. A reporter asked the president about a report of abuses by the Central Intelligence Agency. Here is how President Obama replied:

"Any fair-minded person looking at this would say that some terrible mistakes were made."

And here is President George W. Bush using the same phrase. A reporter asked him about the firing of some prosecutors.

"And he's right, mistakes were made. And I’m frankly not happy about them."

You might hear the passive voice in a courtroom. For legal reasons, sometimes lawyers have to use the passive voice to avoid directly blaming a suspect for a crime. Listen to this courtroom dialog from a popular TV drama The Good Wife. A prosecutor is accusing a person of killing a man named Wagner.

Prosecutor: And how did he kill Wagner?
Defense attorney: Objection!
Prosecutor: Withdrawn. How was Wagner killed?

Did you notice how the prosecutor switched his question from the active to the passive voice? Listen one more time.

Prosecutor: And how did he kill Wagner?
Defense attorney: Objection!
Prosecutor: Withdrawn. How was Wagner killed?

At the beginning of the clip, the prosecutor asked, "How did he kill Wagner?" The defense attorney objected to the question. The prosecutor rephrased the question in the passive voice to avoid blaming the suspect. He asked, "How was Wagner killed?"

Overusing the passive voice is major problem in student writing, even for native speakers. Try to keep your passive sentences under 10 percent of your total. Try converting some of your long sentences into simple subject-verb-object sentences.