Transitive verbs (verbs that take an object) can appear in both active and passive voice. The voice used doesn’t affect the meaning of the sentence but it changes the focus.
Nicolae Paulescu discovered the insulin. (The focus is on Nicolae Paulescu; The subject is Nicolae Paulescu.)
The insulin was discovered by Nicolae Paulescu. (The focus is on the insulin; The subject is the insulin.)
Note: Both sentences have the same meaning but each sentence has different focus.
The school is cleaned every morning.
My motorbike is made in Vietnam.
It isn’t made in Japan.
Is it made in Japan?
This article was written by Dan (Dan wrote this article).
It wasn’t written by his wife.
When was it written?
You can use the passive when is not important/unknown who does/did the action.
My wife’s motorbike was stolen in December.
The passive voice of verbs in simple tenses is formed in this way: will be, am, is, are, was, were + past participle (+ by + agent) (agent = the one who does the action; in the example above the agent is Nicolae Paulescu).
|Past||Brazil won the world cup last year. Focus: Brazil||Last year, the world cup was won by Brazil. Focus: the world cup|
|Present||Inventors make new discoveries every day. Focus: Inventors||New discoveries are made by inventors every day. Focus: New discoveries|
|Future||Technology will control our lives. Focus: Technology||Our lives will be controlled by technology. Focus: Our lives|
"By + noun/pronoun" can be used in passive sentences to tell who or what did the action expressed by the verb. This form, by + noun/pronoun, is not commonly used in English. However, this form is used in the following situations:
Here you have some of the common expressions in passive voice: be accustomed to, be based on, be connected to, be covered with, be derived from, be equipped with, be filled with (by), be formed of (from, by), be known for (as, to+verb), be involved in (with), be linked to, be located in (at, on), be made of (from), be made up of, be noted for, be related to, be shown in (at, on), be suited for, be used for (as, with), be used to + verb etc.
Get + Adjective or Past Participle is commonly used in conversation. I haven’t seen it very often in writing form but for sure is frequently used in spoken English.
|Get + adjective||I got angry about this situation.|
|Get + past participle||I got worried about this situation.|
"It" is often used with the passive form of some verbs such as: believe, confirm, deny, estimate, fear, hope, mention, report, say, think etc. Past expressions such as "It was believed ..." indicate that the ideas mentioned in the sentence have changed.
|Active||People said, “The Earth is flat.”.|
|Passive||It was said, “The Earth is flat.”. It was said that the Earth was flat.|
The passive voice of verbs in perfect tenses is formed as is shown below:
have (will have, have, has, had) + been + past participle (+ by + agent). Usually adverbs of frequency are used after the first auxiliary verb.
|Future Perfect||Within the next few years, companies will have developed several new drugs. Focus: Companies||Within the next few years, several new drugs will have been developed. Focus: Several new drugs|
|Present Perfect||Drug companies have developed many new drugs since 1950. Focus: Drug companies||Many new drugs have been developed since 1950. Focus: Many new drugs|
|Past Perfect||Until 1950, scientists had developed few drugs. Focus: Scientists||Until 1950, few antibiotics had been developed. Focus: Few antibiotics|
Note: As I know, the perfect continuous tenses are not used in passive voice.
The passive voice of verbs in the present and past continuous tenses is formed in this way:
be (am, is, was, were) + being + past participle (+ by + agent). Usually, adverbs of frequency are used after the first auxiliary verb.
|Present Continuous||Today farmers are using sophisticated machines to cultivate their farms. Focus: Farmers||Today, sophisticated machines are being used to cultivate farms. Focus: Sophisticated machines|
|Past Continuous||A hundred years ago, farmers were using primitive tools to cultivate their farms. Focus: Farmers||A hundred years ago, primitive tools were being used to cultivate farms. Focus: Primitive tools|
Note: The future continuous tense and the present and past continuous tense are not used in the passive voice.
The simple passive voice of modal auxiliaries is formed as is shown below:
modal (can, could, may, might, must, ought to, shall, should, will, would) + be + past participle (+ by + agent).
The perfect passive form follows this pattern: modal + have been + past participle.
|Simple Modal||We could conserve more oil today. Focus: We||More oil could be conserved today. Focus: More oil|
|Perfect Modal||We could have conserved more oil in the past. Focus: We||More oil could have been conserved in the past. Focus: More oil|
Note: The perfect form of "must" gives the meaning of probability.
The work must be finished. (Probability or need; it depends on the context)
The work must have been finished. (Probability only)
Remember these three general rules: