Passive Voice

Use of Passive

Passive voice is used when the focus is on the action. It is not important or not known, however, who or what is performing the action.

Example: My bike was stolen.

In the example above, the focus is on the fact that my bike was stolen. I do not know, however, who did it.

Sometimes a statement in passive is more polite than active voice, as the following example shows:

Example: A mistake was made.

In this case, I focus on the fact that a mistake was made, but I do not blame anyone (e.g. You have made a mistake.)

Form of Passive

Subject + finite form of to be + Past Participle (3rd column of irregular verbs)

Example: A letter was written.

When rewriting active sentences in passive voice, note the following:

• the object of the active sentence becomes the subject of the passive sentence
• the finite form of the verb is changed (to be + past participle)
• the subject of the active sentence becomes the object of the passive sentence (or is dropped)

 Example of Passive

 

Passive Sentences with Two Objects

Rewriting an active sentence with two objects in passive voice means that one of the two objects becomes the subject, the other one remains an object. Which object to transform into a subject depends on what you want to put the focus on.

As you can see in the examples, adding by Rita does not sound very elegant. That’s why it is usually dropped.

Personal and Impersonal Passive

Personal Passive simply means that the object of the active sentence becomes the subject of the passive sentence. So every verb that needs an object (transitive verb) can form a personal passive.

Example: They build houses. – Houses are built.

Verbs without an object (intransitive verb) normally cannot form a personal passive sentence (as there is no object that can become the subject of the passive sentence). If you want to use an intransitive verb in passive voice, you need an impersonal construction – therefore this passive is called Impersonal Passive.

Example: he says – it is said

Impersonal Passive is not as common in English as in some other languages (e.g. German, Latin). In English, Impersonal Passive is only possible with verbs of perception (e. g. say, think, know).

Example: They say that women live longer than men. – It is said that women live longer than men.

Although Impersonal Passive is possible here, Personal Passive is more common.

Example: They say that women live longer than men. – Women are said to live longer than men.

The subject of the subordinate clause (women) goes to the beginning of the sentence; the verb of perception is put into passive voice. The rest of the sentence is added using an infinitive construction with 'to' (certain auxiliary verbs and that are dropped).

Sometimes the term Personal Passive is used in English lessons if the indirect object of an active sentence is to become the subject of the passive sentence.

source : http://www.ego4u.com/en/cram-up/grammar/passive

Conditional Sentences (IF-Clauses)

Conditional Sentences / If-Clauses 

Conditional Sentences are also known as Conditional Clauses or If Clauses. They are used to express that the action in the main clause (without if) can only take place if a certain condition (in the clause with if) is fulfilled.

There are three types of Conditional Sentences :

IF Clause Type I

=> refer to the future. An action in the future will only happen if a certain condition is fulfilled by that time. We don't know for sure whether the condition actually will be fulfilled or not, but the conditions seems rather realistic- so we think it is likely to happen.

Form :            if + Simple Present, will-Future

Example : If I find her address, I will send her an invitation.
=> I want to send an invitation to a friend. I just have to find her address. I am quite sure, however, that I will find it.

=> The main clause can also be at the beginning of the sentences. In this case, don't use a comma.
=> I will send her an invitation if I find her address

Note : Main clause and / or if clause might be negative. See Simple Presend and will-Future on how to form negative sentences.
Example  : If I don't see him this afternoon, I will phone him in the evening.

IF-Clause Type II

ð      => refer to situations in the present. An action could happen if the present situation were different. I don’t really expect the situation to change, however. I just imagine,” what would happen if ..”

example : If Ifound her address, I would send her an invitation.

I would like to send an invitation to a friend. I have looked everywhere for her address, but I cannot find it. So now I think it is rather unlikely that I will eventually find her address.

Example: If John had the money, he would buy a Ferrari.

I know John very well and I know that he doesn't have much money, but he loves Ferraris. He would like to own a Ferrari (in his dreams). But I think it is very unlikely that he will have the money to buy one in the near future.

Form

if + Simple Past, main clause with Conditional I (= would + Infinitive)

Example: If I found her address, I would send her an invitation.

The main clause can also be at the beginning of the sentence. In this case, don't use a comma.

Example: I would send her an invitation if I found her address.

Note: Main clause and / or if clause might be negative. See Simple Past and Conditional I on how to form negative sentences.

Example: If I had a lot of money, I wouldn’t stay here.

Were instead of Was

In IF Clauses Type II, we usually use ‚were‘ – even if the pronoun is I, he, she or it –.

Example: If I were you, I would not do this.

IF-Clause Type III
=> refer to situations in the past. An action could have happened in the past if a certain condition had been fulfilled. Things were different then, however. We just imagine, what would have happened if the situation had been fulfilled.

Example: If I had found her address, I would have sent her an invitation. 

Sometime in the past, I wanted to send an invitation to a friend. I didn't find her address, however. So in the end I didn't send her an invitation.

Example: If John had had the money, he would have bought a Ferrari. 

I knew John very well and I know that he never had much money, but he loved Ferraris. He would have loved to own a Ferrari, but he never had the money to buy one.

Form

if + Past Perfect, main clause with Conditional II

Example: If I had found her address, I would have sent her an invitation.

The main clause can also be at the beginning of the sentence. In this case, don't use a comma.

Example: I would have sent her an invitation if I had found her address.

Note: Main clause and / or if clause might be negative. See Past Perfect and Conditional II on how to form negative sentences.

Example: If I hadn’t studied, I wouldn’t have passed my exams.

source : http://www.ego4u.com/en/cram-up/grammar/conditional-sentences/