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 verb)

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)

Examples of Passive

Tense		Subject	Verb	Object
Simple Present	Active:	Rita	writes	a letter.
	Passive:	A letter	is written	by Rita.
Simple Past	Active:	Rita	wrote	a letter.
	Passive:	A letter	was written	by Rita.
Present Perfect	Active:	Rita	has written	a letter.
	Passive:	A letter	has been written	by Rita.
Future I	Active:	Rita	will write	a letter.
	Passive:	A letter	will be written	by Rita.
Hilfsverben	Active:	Rita	can write	a letter.
	Passive:	A letter	can be written	by Rita.

Examples of Passive Level: upper intermediate

Tense		Subject	Verb	Object
Present Progressive	Active:	Rita	is writing	a letter.
	Passive:	A letter	is being written	by Rita.
Past Progressive	Active:	Rita	was writing	a letter.
	Passive:	A letter	was being written	by Rita.
Past Perfect	Active:	Rita	had written	a letter.
	Passive:	A letter	had been written	by Rita.
Future II	Active:	Rita	will have written	a letter.
	Passive:	A letter	will have been written	by Rita.
Conditional I	Active:	Rita	would write	a letter.
	Passive:	A letter	would be written	by Rita.
Conditional II	Active:	Rita	would have written	a letter.
	Passive:	A letter	would have been written	by Rita.

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.

	Subject	Verb	Object 1	Object 2
Active:	Rita	wrote	a letter	to me.
Passive:	A letter	was written	to me	by Rita.
Passive:	I	was written	a letter	by Rita.

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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.

http://www.ego4u.com/en/cram-up/grammar/passive/exercises
http://www.ego4u.com/en/cram-up/grammar/passive/exercises?02
http://www.ego4u.com/en/cram-up/grammar/passive/exercises?03
http://www.ego4u.com/en/cram-up/grammar/passive/exercises?04

Gerunds and Infinitives

1. A gerund is a noun made from a verb by adding "-ing." The gerund form of the verb "read" is "reading." You can use a gerund as the subject, the complement, or the object of a sentence.

Examples:

• Reading helps you learn English. subject of sentence
• Her favorite hobby is reading. complement of sentence
• I enjoy reading. object of sentence

Gerunds can be made negative by adding "not."

Examples:

• He enjoys not working.
• The best thing for your health is not smoking.

2. Infinitives are the "to" form of the verb. The infinitive form of "learn" is "to learn." You can also use an infinitive as the subject, the complement, or the object of a sentence.

Examples:

• To learn is important. subject of sentence
• The most important thing is to learn. complement of sentence
• He wants to learn. object of sentence

Infinitives can be made negative by adding "not."

Examples:

• I decided not to go.
• The most important thing is not to give up.

3. Both gerunds and infinitives can be used as the subject or the complement of a sentence. However, as subjects or complements, gerunds usually sound more like normal, spoken English, whereas infinitives sound more abstract. In the following sentences, gerunds sound more natural and would be more common in everyday English. Infinitives emphasize the possibility or potential for something and sound more philosophical. If this sounds confusing, just remember that 90% of the time, you will use a gerund as the subject or complement of a sentence.

Examples:

• Learning is important. normal subject
• To learn is important. abstract subject - less common
• The most important thing is learning. normal complement
• The most important thing is to learn. abstract complement - less common

4. As the object of a sentence, it is more difficult to choose between a gerund or an infinitive. In such situations, gerunds and infinitives are not normally interchangeable. Usually, the main verb in the sentence determines whether you use a gerund or an infinitive.

Examples:

• He enjoys swimming. "Enjoy" requires a gerund.
• He wants to swim. "Want" requires an infinitive.

5. Some verbs are followed by gerunds as objects.

Examples:

• She suggested going to a movie.
• Mary keeps talking about her problems.

6. Some verbs are followed by infinitives.

Examples:

• She wants to go to a movie.
• Mary needs to talk about her problems.

http://wwwedu.ge.ch/cptic/prospective/projets/anglais/exercises/gerund1.htm

Full infinitive

Full infinitive

Una frase infinitiva es un grupo de palabras acompañadas de un infinitivo (no toda la frase es infinitiva).
Ejemplo: To help other is a good thing

En las frases infinitivas pueden haber 2: sujeto y objeto.
 Ejemplo: To study will make you a better student
               Katty wants to study alone

Hay verbos que siempre estan seguidos por infinitives.
Ejemplo: Hesitate She didn’t hesitate to tell the boss that some employees were stealing office supplies.
Offer The Martin Family offered to watch their neighbor’s dog for the whole week.
Promise The school promised to help me find an apartment.
 Want We want to visit all of the historic sites in Tehran.

Estas palabras raras veces van seguidas por gerundios (que son verbos con la terminación ing que significa ando, endo)

El infinitivo y el gerundio muchas veces pueden usados en la misma oración sin cambiarle el significado.
Ejemplo: The children like to go to the zoo.
The children like going to the zoo.

Pero para otros verbos si hay diferencia.
Ejemplo: Louise stopped smoking. ( esto significa que esa persona ya no fuma mas)
Louise stopped to smoke.  ( en esta situación ella dejo de hacer una actividad porque quería fumar)


El “bare infinitive” o infinitivo sin “to”:
El infinitivo sin “to” (bare infinitive) se llama así porqué carece de la particula “to”: (to) work. Eso hace que se pueda confundir fácilmente con la forma de presente del verbo. Como se trata de un infinitivo, aunque sin “to”, esta forma verbal siempre acompaña a otro verbo y los dos hacen referencia al mismo sujeto:
He made me write the essay again.
She helped me carry the bags upstairs.
Este tipo de infinitivo aparece en algunas estructuras muy específicas del inglés:
1. Con los verbos make y help
2. Con las expresiones “would rather” ( = would prefer) y “had better” (= should)
Would rather
Normalmente, esta expresión se utiliza con un sujeto de primera persona singular, dado que se trata de una preferencia:
I’d rather stay at home and sleep this weekend.
Pero también podemos utilizarla con otros sujetos:
My husband would rather spend his holiday in the States.
La versión negativa de esta expresión es would rather not:
I’d rather not go out tonight. I’m exhausted.
Para expresar una preferencia que implica a otra persona, utilizamos la siguiente estructura:
Sujeto1 + would rather + sujeto2 + past tense
I’d rather  you came to the party. (Preferiria que vinieras a la fiesta)
My wife would rather we didn’t play football in the garden.
Had better
Esta estructura se utiliza par expresar consejos y puede tener todo tipo de sujetos, aunque es menos habitual con el pronombre de primera persona singular (porque normalmente los consejos se dirigen a los otros):
He’d better study more if he wants to pass the exam.
It’s late. I’d better get going.
La versión negativa de esta expresión es had better not:
She’d better not waste her time on such trifles.
Importante:
Tanto would rather como had better tienen la forma contraida “d”, por lo tanto nos tenemos que fijar en la segunda parte de la expresión para decidir si “d” sustituye a “would” o a “had”.

Gerundio:
El gerundio se forma en inglés añadiendo la desinencia 'ing' (sin 'to') al infinitivo del verbo.
To play / jugar            playing / jugando
CONSIDERACIONES
- Cuando el infinitivo termina en consonante precedida de una sola vocal pronunciada más fuerte, la consontante última se duplica:
To sit sitting            (sentarse)
- Cuando el infinitivo termina en '-e' muda, ésta desaparece.
To write writing            (escribir)
- Cuando el infinitivo termina en 'ie' cambia a 'y' + 'ing'
To lie lying            (mentir)
USO DEL GERUNDIO
- Como sujeto en una expresión
Reading English is easier than speaking it / Leer inglés es más fácil que hablarlo
- En algunas expresiones de prohibición
No smoking / Prohibido fumar
- Se emplea para obtener la forma progresiva de los verbos
I am reading a book / Estoy leyendo un libro
- Cuando a un verbo precede de forma inmediata una preposición se utiliza la forma de gerundio.
After swimming I felt cold / Después de nadar me sentí resfriado
They had difficulty in finding a parking place / Tuvieron dificultad para encontrar una plaza de aparcamiento
- Como complemento de un verbo
His hobby is painting / Su hobby es la pintura
- Se utiliza frecuentemente después de los verbos 'to go' y 'to come'
Come sailing with us next Saturday / Ven a navegar con nosotros el próximo sábado

http://misdeberes.es/tarea/51268

Modal's

 
Modals must/have to (Necessity – Deduction)

In this series of lessons on modals we are dividing the meanings of modals into intrinsic and extrinsic meanings. In this lesson we are looking at the intrinsic and extrinsic meanings of ‘must’ and ‘have to/have got to’.
Look at these sentences:
My neighbours must control or discipline their children. They’re too noisy.
You’ve been working all week. You must be tired.
In the first sentence ‘must’ shows that the speaker sees this as a necessity. This meaning is intrinsic as it implies human control.
In the second sentence ‘must’ is used because the speaker is coming to a conclusion or deducing a situation. This meaning is extrinsic as the implication involves human judgement.

Must/ have to – Necessity

Must and have to are used to show that something is necessary:
The accommodation has to be booked well in advance.
The wine must be served chilled.
Must is used in more formal situations when stating rules:
Students must present their I.D. when borrowing books from the library.
Guests must refrain from smoking on the premises.
Have to/ have got to is more commonly used to describe a necessity which is not the speaker’s decision or in the speaker’s control:
We have to be there at least an hour before we are supposed to leave.
You’ve got to wear a tie to go in there.
‘Have got to’ is used in informal English although ‘have to’ is normally used with past simple in negatives and question forms. If ‘have’ is contracted then ‘have got to’ is used.
I had to go back to the restaurant for the umbrella I’d left there.
Where did you have to go?
He’s got to understand it’s not always about him.
‘Must’ has no past, perfect, continuous, infinitive or –ing and ‘have to’ is used. ‘Must’ is used for necessity in the future. ‘Have to’ is usually used for questions. ‘Must’ in question forms is seen as too formal or archaic.  Must is usually used for a necessity that is also a pleasure. I must go and see my sister. It’s her birthday tomorrow. = this is necessary but also a pleasure.
‘Mustn’t’ has a different meaning to ‘don’t have to’:
You must/have to wear a tie. = this is necessary
You don’t have to wear a tie. = this isn’t necessary but you can if you want to.
You mustn’t wear a tie. = this is necessary. Do not wear a tie.

Must/have to – deduction

Must is also used to deduce a situation about present and future events. Must + have + past participle is used for past events and their deduced result.
It must be very difficult to move to a new city where you don’t know anyone.
It must have been hard to get used to a different climate.
Jane isn’t at home. She must be doing the shopping.
Have to is used when the outcome is closer to what will happen.
There has to be a cheaper flight than this one. Keep looking.
They’ve got to make this easier to understand very soon.
http://www.learnenglish-online.com/grammar/modals/tests/modaltest2.html