Interchange of active and passive voice

A sentence in the active form can be changed into the passive form. Similarly a sentence in the passive form can be changed into the active form.

  • Active: Brutus stabbed Caesar.
  • Passive: Caesar was stabbed by Brutus.
  • Active: The boy killed the spider.
  • Passive: The spider was killed by the boy.
  • Active: The teacher punished the boy.
  • Passive: The boy was punished by the teacher.
  • Active: His behavior vexes me.
  • Passive: I am vexed by his behavior.

When it is clear who the agent (doer of the action) is, it is not necessary to mention it in the passive form. In fact, this omission often makes the sentence look neater.

  • Active: The audience loudly cheered the Mayor’s speech.
  • Passive: The Mayor’s speech was loudly cheered (by the audience).

The active voice is preferred when the agent (i.e. the person who performs the action) is to be made prominent. The passive voice is preferred when the agent is unknown or when we do not care to mention the agent.

The passive form is preferred in the following sentences because the agent is either unknown or unimportant.

  • Passive: My pocket has been picked.
  • Active: Somebody has picked my pocket.
  • Passive: I shall be obliged to go.
  • Active: Circumstances will oblige me to go.
  • Passive: Promises should be kept.
  • Active: One should keep one’s promises.