PRESENT PERFECT & CONDITIONALS

16 de noviembre de 2010 - 16:23

Present Perfect Tense

The present perfect tense is a rather important tense in English, but it gives speakers of some languages a difficult time. That is because it uses concepts or ideas that do not exist in those languages. In fact, the structure of the present perfect tense is very simple. The problems come with the use of the tense. In addition, there are some differences in usage between British and American English.

In this lesson we look at the structure and use of the present perfect, followed by a quiz to check your understanding:

*The present perfect tense is really a very interesting tense, and a very useful one. Try not to translate the present perfect tense into your language. Just try to accept the concepts of this tense and learn to "think" present perfect! You will soon learn to like the present perfect tense!

How do we make the Present Perfect Tense?

The structure of the present perfect tense is:

subject	+	auxiliary verb	+	main verb
		have		past participle

Here are some examples of the present perfect tense:

	subject	auxiliary verb		main verb
+	I	have		seen	ET.
+	You	have		eaten	mine.
-	She	has	not	been	to Rome.
-	We	have	not	played	football.
?	Have	you		finished?
?	Have	they		done	it?

Contractions with the present perfect tense

When we use the present perfect tense in speaking, we usually contract the subject and auxiliary verb. We also sometimes do this when we write.

I have	I’ve
You have	You’ve
He has She has It has John has The car has	He’s She’s It’s John’s The car’s
We have	We’ve
They have	They’ve

Here are some examples:

I’ve finished my work.
John’s seen ET.
They’ve gone home.

*He’s or he’s??? Be careful! The ’s contraction is used for the auxiliary verbs have and be. For example, "It’s eaten" can mean:

It has eaten. [present perfect tense, active voice]
It is eaten. [present tense, passive voice]

It is usually clear from the context.

1. Present perfect tense for experience

We often use the present perfect tense to talk about experience from the past. We are not interested in when you did something. We only want to know if you did it:

I have seen ET.
He has lived in Bangkok.
Have you been there?
We have never eaten caviar.

past

present

future

!!!

The action or state was in the past.

In my head, I have a memory now.

Connection with past: the event was in the past.
Connection with present: in my head, now, I have a memory of the event; I know something about the event; I have experience of it.

2. Present perfect tense for change

We also use the present perfect tense to talk about a change or new information:

I have bought a car.
past	present	future
-	+
Last week I didn’t have a car.	Now I have a car.

John has broken his leg.
past	present	future
+	-
Yesterday John had a good leg.	Now he has a bad leg.

Has the price gone up?
past	present	future
+	-
Was the price $1.50 yesterday?	Is the price $1.70 today?

The police have arrested the killer.
past	present	future
-	+
Yesterday the killer was free.	Now he is in prison.

Connection with past: the past is the opposite of the present.
Connection with present: the present is the opposite of the past.

*Americans do not use the present perfect tense so much as British speakers. Americans often use the past tense instead. An American might say "Did you have lunch?", where a British person would say "Have you had lunch?"

3. Present perfect tense for continuing situation

We often use the present perfect tense to talk about a continuing situation. This is a state that started in the past and continues in the present (and will probably continue into the future). This is a state (not an action). We usually use for or since with this structure.

I have worked here since June.
He has been ill for 2 days.
How long have you known Tara?

past

present

future

The situation started in the past.

It continues up to now.

(It will probably continue into the future.)

Connection with past: the situation started in the past.
Connection with present: the situation continues in the present.

For & Since with Present Perfect Tense

We often use for and since with the present perfect tense.

We use for to talk about a period of time - 5 minutes, 2 weeks, 6 years.
We use since to talk about a point in past time - 9 o’clock, 1st January, Monday.

for	since
a period of time	a point in past time
	x------------
20 minutes	6.15pm
three days	Monday
6 months	January
4 years	1994
2 centuries	1800
a long time	I left school
ever	the beginning of time
etc	etc

Here are some examples:

I have been here for 20 minutes.
I have been here since 9 o’clock.
John hasn’t called for 6 months.
John hasn’t called since February.
He has worked in New York for a long time.
He has worked in New York since he left school.

*For can be used with all tenses. Since is usually used with perfect tenses only.

English Conditionals

There are several structures in English that are called conditionals.

"Condition" means "situation or circumstance". If a particular condition is true, then a particular result happens.

If y = 10 then 2y = 20
If y = 3 then 2y = 6

There are three basic conditionals that we use very often. There are some more conditionals that we do not use so often.

In this lesson, we will look at the three basic conditionals as well as the so-called zero conditional. We’ll finish with a quiz to check your understanding.

People sometimes call conditionals "IF" structures or sentences, because there is usually (but not always) the word "if" in a conditional sentence.

Structure of Conditional Sentences

The structure of most conditionals is very simple. There are two basic possibilities. Of course, we add many words and can use various tenses, but the basic structure is usually like this:

IF	condition	result
IF	y = 10	2y = 20

or like this:

result	IF	condition
2y = 20	IF	y = 10

First Conditional: real possibility

We are talking about the future. We are thinking about a particular condition or situation in the future, and the result of this condition. There is a real possibility that this condition will happen. For example, it is morning. You are at home. You plan to play tennis this afternoon. But there are some clouds in the sky. Imagine that it rains. What will you do?

IF	condition	result
	present simple	WILL + base verb
If	it rains	I will stay at home.

Notice that we are thinking about a future condition. It is not raining yet. But the sky is cloudy and you think that it could rain. We use the present simple tense to talk about the possible future condition. We use WILL + base verb to talk about the possible future result. The important thing about the first conditional is that there is a real possibility that the condition will happen. Here are some more examples (do you remember the two basic structures: [IF condition result] and [result IF condition]?):

IF	condition	result
	present simple	WILL + base verb
If	I see Mary	I will tell her.
If	Tara is free tomorrow	he will invite her.
If	they do not pass their exam	their teacher will be sad.
If	it rains tomorrow	will you stay at home?
If	it rains tomorrow	what will you do?

result	IF	condition
WILL + base verb		present simple
I will tell Mary	if	I see her.
He will invite Tara	if	she is free tomorrow.
Their teacher will be sad	if	they do not pass their exam.
Will you stay at home	if	it rains tomorrow?
What will you do	if	it rains tomorrow?

Sometimes, we use shall, can, or may instead of will, for example: If you are good today, you can watch TV tonight.

Second Conditional: unreal possibility or dream

The second conditional is like the first conditional. We are still thinking about the future. We are thinking about a particular condition in the future, and the result of this condition. But there is not a real possibility that this condition will happen. For example, you do not have a lottery ticket. Is it possible to win? No! No lottery ticket, no win! But maybe you will buy a lottery ticket in the future. So you can think about winning in the future, like a dream. It’s not very real, but it’s still possible.

IF	condition	result
	past simple	WOULD + base verb
If	I won the lottery	I would buy a car.

Notice that we are thinking about a future condition. We use the past simple tense to talk about the future condition. We use WOULD + base verb to talk about the future result. The important thing about the second conditional is that there is an unreal possibility that the condition will happen.

Here are some more examples:

IF	condition	result
	past simple	WOULD + base verb
If	I married Mary	I would be happy.
If	Ram became rich	she would marry him.
If	it snowed next July	would you be surprised?
If	it snowed next July	what would you do?

result	IF	condition
WOULD + base verb		past simple
I would be happy	if	I married Mary.
She would marry Ram	if	he became rich.
Would you be surprised	if	it snowed next July?
What would you do	if	it snowed next July?

Sometimes, we use should, could or might instead of would, for example: If I won a million dollars, I could stop working.

Third Conditional: no possibility

The first conditional and second conditionals talk about the future. With the third conditional we talk about the past. We talk about a condition in the past that did not happen. That is why there is no possibility for this condition. The third conditional is also like a dream, but with no possibility of the dream coming true.

Last week you bought a lottery ticket. But you did not win. :-(

	condition	result
	Past Perfect	WOULD HAVE + Past Participle
If	I had won the lottery	I would have bought a car.

Notice that we are thinking about an impossible past condition. You did not win the lottery. So the condition was not true, and that particular condition can never be true because it is finished. We use the past perfect tense to talk about the impossible past condition. We use WOULD HAVE + past participle to talk about the impossible past result. The important thing about the third conditional is that both the condition and result are impossible now.

Sometimes, we use should have, could have, might have instead of would have, for example: If you had bought a lottery ticket, you might have won.

Look at some more examples in the tables below:

IF	condition	result
	past perfect	WOULD HAVE + past participle
If	I had seen Mary	I would have told her.
If	Tara had been free yesterday	I would have invited her.
If	they had not passed their exam	their teacher would have been sad.
If	it had rained yesterday	would you have stayed at home?
If	it had rained yesterday	what would you have done?

result	IF	condition
WOULD HAVE + past participle		past perfect
I would have told Mary	if	I had seen her.
I would have invited Tara	if	she had been free yesterday.
Their teacher would have been sad	if	they had not passed their exam.
Would you have stayed at home	if	it had rained yesterday?
What would you have done	if	it had rained yesterday?

Zero Conditional: certainty

We use the so-called zero conditional when the result of the condition is always true, like a scientific fact.

Take some ice. Put it in a saucepan. Heat the saucepan. What happens? The ice melts (it becomes water). You would be surprised if it did not.

IF	condition	result
	present simple	present simple
If	you heat ice	it melts.

Notice that we are thinking about a result that is always true for this condition. The result of the condition is an absolute certainty. We are not thinking about the future or the past, or even the present. We are thinking about a simple fact. We use the present simple tense to talk about the condition. We also use the present simple tense to talk about the result. The important thing about the zero conditional is that the condition always has the same result.

We can also use when instead of if, for example: When I get up late I miss my bus.

Look at some more examples in the tables below:

IF	condition	result
	present simple	present simple
If	I miss the 8 o’clock bus	I am late for work.
If	I am late for work	my boss gets angry.
If	people don’t eat	they get hungry.
If	you heat ice	does it melt?

result	IF	condition
present simple		present simple
I am late for work	if	I miss the 8 o’clock bus.
My boss gets angry	if	I am late for work.
People get hungry	if	they don’t eat.
Does ice melt	if	you heat it?

Conditionals: Summary

Here is a chart to help you to visualize the basic English conditionals. Do not take the 50% and 10% figures too literally. They are just to help you.

probability

conditional

example

time

100%

zero conditional

If you heat ice, it melts.

any time

50%

first conditional

If it rains, I will stay at home.

future

10%

second conditional

If I won the lottery, I would buy a car.

future

third conditional

If I had won the lottery, I would have bought a car.

past

EXAMPLES

* How many albums have you recorded in your live?

= I have recorded five albums

* How long have you lived in the united states?

= I have lived in the united sattes since 1998

*Have you ever been sick?

=Yes, I have been sick. when I was a child

*Have you had good luck with your music?

=Yes, I have had the best good luck

*What do you wait about your future?

= every day be a best person with my family and with my sons

*How many children have you had?

=I had 3 sons homed moon, dove and donte

*When did you begin your artistic career?

=Fifteen years ago in medellin arty

*Have you been involved with politics?

=Yes, I’ve participaded in the European Parliamenth and I was the first singer present as a symbol of support for the cause mine

*How many awards have you won?

=Appromimately ten grammy awards

*Which has been the most successfol album in your life?

=My most successfull album has been "A moment"

THE PASSIVE: to be + past participle

Form:

* We form the passive with the verb to be and the past participle of the main verb

ACTIVE PASIVE

present simple: He feeds the dogs twice a day The dog is fed twice a day

past simple: He fed the dog yesterday The dog was fed yesterday

pesent perfect simple: He has feed the dog The dog has been fed

future simple: He will feed the dog The dog will be fed

modal: He should feed the dog The dog should be fed

* We form questions by putting the verb to be before the subject, is this car made in japan ?

*We form negations with the word Not. His bicycle was not/ wasn’t stolen last night.

Turning from Active into passive

To turn a sentence from the active into the passive

a) the oblect of the active sentence becomes

the subject in the passive sentence

b) the active verb changes into a passive form.

c) the subject of the active sentence becomes the agent.

subject verb object

ACTIVE susan made a cake

subject verb agent

PASIVE A cake was made by susan

Only the verbs that take an obejct can be turned into the passive

Tom watered the plants - The plants were watered by tom. But it is raining today (this sentence cannot be turned into the passive because the verb does not take an object)

When the subject of the actives sentence is one os the followin words: people, one, someone/somebody, they, he, etc., the agentis often,omittes in the passive sentence.

someone willfeed the dog .-. The dog will be fed.

Object pronouns (me, you, him, etc..) become subject pronouns (i, you, he, etc..) in the passive. she gave me some monery.- I was given some money
When the verb of the active sentence is followed by a preposition, the preposition is kept in the passive sentence as well. someone broken into our house last night.- Our house was broken into last night

USE

We use the passive when we want to show that the action of the verb is more important than the agent. (i , e. the person or thing doing or causing the action). the agent is introduced with the preposition by and is mentioned only when it is important or nedds to be stated. Oliver Twist was written by charles dickens.

The agent is not mentioned when. a)it is unknown. His car was stolen last nigth (we don’t know who stole his car). b) it is unimportant. breakfast will be sevrd at 7.30 (the agent is unimportant) c) it is obvious from the context. He has been arrest.( it is obvious who arrested him the police).

Example:

1. Someone will meet you at the airpot.

......you will be met at the airport...

2. He has mended the puncture.

....The puncture has been mended by him...

3. Sam willa fix the roof.

.....The roof will be fixed by sam

4. The clown will entertain the children

.....The children will be entertain by the clown....