The 3 articles in English are a, an and the. The
learner has to decide noun-by-noun which one of the articles to use (Instead of an article, the noun can also be preceded by a determiner such as this, that, some, many or my, his, our, etc).
In fact, there are 4 choices to make, because sometimes no article is
necessary. Native-speakers, of course, use the articles correctly
without thinking in everyday spoken langauge.
English learners, on the
other hand, need to have some guidelines for making the right choice -
particularly those learners whose own language does not have articles,
such as Japanese or Korean. The guidelines that follow here should help
ESL students to a basic understanding of English article use.
The most important first step in choosing the correct article is to categorize the noun as count or uncountin its context. (To repeat: It is very important to know that many nouns can be count in one context and uncount in another. A common example is hair: She has red hair (uncount) - There are two hairs in my soup! (count). So before deciding which article, if any, to use in front of any given noun, you need to know if the noun is countable or not in that context).
- A count noun is a noun that can have a number in front of it: 1 teacher, 3 books, 76 trombones, 1,000,000 people.
- An uncount noun is a noun that cannot have a number put in front of it: 1 water, 2 lucks, 10 airs, 21 oils, 39 informations. Once you have correctly categorized the noun (using your dictionary if necessary), the following "rules" apply:
Uncount nouns
You cannot say a/an with an uncount noun.
You cannot put a number in front of an uncount noun. (You cannot make an uncount noun plural.)
You use an uncount noun with no article if you mean that thing in general.
You use the with an uncount noun when you are talking about a particular example of that thing.
Count nouns
You can put a number in front of a count noun. (You can make a count noun plural.)
You can put both a/an and the in front of a count noun.
You must put an article in front of a singular count noun.
You use a plural count noun with no article if you mean all or any of that thing.
You usually use a/an with a count noun the first time you say or write that noun.
You use the with count nouns:
the second and subsequent times you use the noun in a piece of speech or writing
when the listener knows what you are referring to (maybe because there is only one of that thing)
You use an (not a) when the next word (adverb, adjective, noun) starts with a vowel sound.
Note:
The above rules apply whether there is or there is not an adjective in front of the noun.
Some nouns can be either count or uncount, depending on the context and meaning:
Do you have paper? I want to draw a picture. (uncount = a sheet of paper)
Can you get me a paper when you’re at the shop? (count = a newspaper)
Uncount nouns are often preceded by phrases such as: a lot of .. (luck), a piece of .. (cake), a bottle of .. (milk), a grain of .. (rice).
Following are some of the most important guidelines listed above, with example sentences:
1. You use an uncount noun with no article if you mean all or any of that thing.
I need help!
I don't eat cheese.
Do you like music?
2. You use the with an uncount noun when you are talking about a particular example of that thing.
Thanks for the help you gave me yesterday.
I didn't eat the cheese. It was green!
Did you like the music they played at the dance?
3. You usually use a/an with a count noun the first time you say or write that noun.
Can I borrow a pencil, please?
There's a cat in the garden!
Do you have an mp3 player?
4. You use the with count nouns the
second and subsequent times you use the noun, or when the listener
already knows what you are referring to (maybe because there is only one
of that thing).
Where's the pencil I lent you yesterday?
I think the cat belongs to the new neighbours.
I dropped the mp3 player and it broke.
Please shut the door!
5. You use a plural count noun with no article if you mean all or any of that thing.
I don't like dogs.
Do they have children?
I don't need questions. Give me answers!
6. The above rules apply whether there is or there is not an adjective in front of the noun.
I don't eat German cheese.
Can I borrow a red pencil, please?
There's an extremely large cat in the garden!
I don't like small, noisy children.
The definite article
The word "the" is one of the most common words in English. It is our
only definite article. Nouns in English are preceded by the definite
article when the speaker believes that the listener already knows what
he is referring to. The speaker may believe this for many different
reasons, some of which are listed below.
When to use "the"
General rules
Use the to refer to something which has already been mentioned.
Examples
On Monday, an unarmed man stole $1,000 from the bank. The thiefhasn't been caught yet.
I was walking past Benny's Bakery when I decided to go into the bakery to get some bread.
There's a position available in my team. The job will involve some international travel.
Use the when you assume there is just one of something in that place, even if it has not been mentioned before.
Examples
We went on a walk in the forest yesterday.
Where is the bathroom?
Turn left and go to number 45. Our house is across from the Italian restaurant.
My father enjoyed the book you gave him.
Use the in sentences or clauses where you define or identify a particular person or object.
Examples
The man who wrote this book is famous.
I scratched the red car parked outside.
I live in the small house with a blue door.
He is the doctor I came to see.
Use the to refer to people or objects that are unique.
Examples
The sun rose at 6:17 this morning.
You can go anywhere in the world.
Clouds drifted across the sky.
The president will be speaking on TV tonight.
The CEO of Total is coming to our meeting.
Use the before superlatives and ordinal numbers.
Examples
This is the highest building in New York.
She read the last chapter of her new book first.
You are the tallest person in our class.
This is the third time I have called you today.
Use the with adjectives, to refer to a whole group of people.
Examples
The French enjoy cheese.
The elderly require special attention.
She has given a lot of money to the poor.
Use the with decades.
Examples
He was born inthe seventies.
This is a painting from the 1820's.
Use the with clauses introduced by only.
Examples
This isthe only day we've had sunshine all week.
You are the only person he will listen to.
The only tea I like is black tea.
Proper nouns
Use the with names of geographical areas, rivers, mountain ranges, groups of islands, canals, and oceans.
Examples
They are travelling in the Arctic.
Our ship crossed the Atlantic in 7 days.
I will go on a cruise down the Nile.
Hiking across the Rocky Mountains would be difficult.
Use the with countries that have plural names.
Examples
I have never been to the Netherlands.
Do you know anyone who lives in the Philippines?
Use the with countries that include the words "republic", "kingdom", or "states" in their names.
Examples
She is visiting the United States.
James is from the Republic of Ireland.
Use the with newspaper names.
Examples
I read it in the Guardian.
She works for the New York Times.
Use the with the names of famous buildings, works of art, museums, or monuments.
Examples
Have you been to the Vietnam Memorial?
We went to the Louvre and saw the Mona Lisa.
I would like to visitthe Eiffel Tower.
I saw King Lear at the Globe.
Use the with the names of hotels & restaurants, unless these are named after a person.
Examples
They are staying at the Hilton on 6th street.
We ate at the Golden Lion.
Use the with the names of families, but not with the names of individuals.
Examples
We're having dinner with the Smiths tonight.
The Browns are going to the play with us.
When not to use "the"
Do not use the with names of countries (except for the special cases above).
Examples
Germany is an important economic power.
He's just returned from Zimbabwe.
Do not use the with the names of languages.
Examples
French is spoken in Tahiti.
English uses many words of Latin origin.
Indonesian is a relatively new language.
Do not use the with the names of meals.
Examples
Lunch is my favorite meal.
I like to eat breakfast early.
Do not use the with people's names.
Examples
John is coming over later.
Mary Carpenter is my boss.
Do not use the with titles when combined with names.
Examples
Prince Charles is Queen Elizabeth's son.
President Kennedy was assassinated in Dallas.
Do not use the after the 's possessive case.
Examples
His brother's car was stolen.
Peter's house is over there.
Do not use the with professions.
Examples
Engineering is a well-paid career.
He'll probably study medicine.
Do not use the with names of shops.
Examples
I'll get the card at Smith's.
Can you go to Boots for me?
Do not use the with years.
Examples
1948 was a wonderful year.
He was born in 1995.
Do not use the with uncountable nouns.
Examples
Rice is an important food in Asia.
Milk is often added to tea in England.
War is destructive.
Do not use the with the names of individual mountains, lakes and islands.
Examples
Mount McKinley is the highest mountain in Alaska.
She lives near Lake Windermere.
Have you visited Long Island?
Do not use the with most names of towns, streets, stations and airports.
Modal verbs are for example may, can, must, should, need.
They express an ability, permission, wish etc. to do something. (I may,
can, must swim.) Many modal verbs cannot be used in all of the English
tenses. That's why we need to know the substitutes to these modal verbs.
Modal Verb
Substitute
Example
must
to have to
I must swim. = I have to swim.
must not
not to be allowed to
I must not swim. = I am not allowed to swim.
can
to be able to
I can swim. = I am able to swim.
may
to be allowed to
I may swim. = I am allowed to swim.
need
to have to
I need to swim. = I have to swim.
need not
not to have to
I need not swim. = I don't have to swim.
shall / should/ ought to
to be supposed to / to be expected to / to be to
I shall / should / ought to swim. = I am supposed to swim. / I am expected to swim. / I am to swim.
Modal Verbs - Can
El verbo 'Can' pertenece a los verbos modales y se ubica antes del
verbo principal en infinitivo. Significa 'poder'. Se utiliza para
expresar habilidad, permiso.
I can - puedo
Affirmative
I can play the trumpet.
Yo puedo/sé tocar la trompeta.
We can take a taxi to the airport.
Podemos tomar un taxi hasta el aeropuerto.
Mary can be very stubborn sometimes.
Mary puede ser muy terca a veces.
You can sit here if you like.
Puedes sentarte aquí si quieres.
It can take longer than we thought.
(Esto) Puede tardar más de lo que pensábamos.
Nobody can understand that.
Nadie puede entender eso.
Your decision can change our lives.
Tu decisión puede cambiarnos la vida.
Negative
I can not swim.
No puedo/sé nadar.
That cannot be true.
Eso no puede ser cierto.
You can't tell me what to do.
No puedes decirme qué hacer
Interrogative
Can Peter speak German?
¿Puede/sabe Peter hablar alemán?
Can you help me with my homework?
¿Me puedes ayudar con mi tarea?
Can + have
Paul can have gone to Maria's.
Paul puede haber ido a lo de María.
They can't have left without us.
Ellos no pueden haberse ido sin nosotros.
Jane can't have said that.
Jane no puede haber dicho eso.
Modal Verbs - Could
El verbo 'Could' Expresa poca probabilidad o condicionalidad.
Significa: podría, pude, podía, pudiera de acuerdo con el contexto: I
could dance if I could practice.
I could - podría / pude / podía / pudiera
Affirmative
You could be wrong.
Podrías estar equivocado.
They could manage without us.
Ellos pudieron/podrían arreglárselas sin nosotros.
I could help Ann if she only let me.
Yo podría ayudar a Ann si tan solo me dejara.
This new plan could be very risky.
Este nuevo plan podría ser muy riesgoso.
The news could kill Mr. Taylor.
La noticia podría matarlo al señor Taylor.
Anybody could be chosen for the job.
Cualquiera podría ser elegido para el trabajo.
I could go back and bring Kate with me.
Yo podría/pude volver y traer a Kate conmigo.
Negative
I couldn't see very clearly.
Yo no pude/podría ver muy claramente.
Mrs. Jones couldn't stand the smell.
La señora Jones no pudo/podría soportar el olor.
We couldn't leave you alone.
No podríamos dejarte solo.
Interrogative
Could you open the window?
¿Pudiste/podrías abrir la ventana?
Could they escape?
¿Pudieron/podrían escapar?
Could + have
You could have told me you weren't at home!
¡Podrías haberme dicho que no estabas en casa!
It could have been worse.
Pudo/podría haber sido peor.
John couldn't have done that.
John no pudo/podría haber hecho eso.
Modal Verbs - May
El verbo 'may' se utiliza para expresar cierto grado de probabilidad
de una acción o grado de certeza: It may rain today. Significa: podría,
quizás, puede que.
I may - podría / quizás / puede que
Affirmative
We may stay here for the night.
Podríamos pasar la noche aquí.
Jack may be telling the truth.
Puede que Jack esté diciendo la verdad.
You may ask three questions.
Puedes hacer tres preguntas.
I may visit Susan on Monday.
Quizás la visite a Susan el lunes.
The road may be blocked.
El camino podría estar bloqueado.
That may be a good idea.
(Esa) Quizá sea una buena idea.
Carol may go when she finishes.
Carol puede/podrá ir cuando termine.
Negative
Mr. Johnson may not remember anything.
Puede que el señor Johnson no recuerde nada.
You may not leave the classroom without permission.
Usted no puede salir del aula sin permiso.
I may not come next week.
Quizá no venga la semana que viene.
Interrogative
May I go to the bathroom?
¿Puedo ir al baño?
May you take this to Mr. Richards?
¿Podrías llevarle esto al señor Richards?
May + have
Vicky may have told me.
Puede que Vicky me haya dicho.
They may not have known that.
Puede que ellos no hayan sabido eso.
I may have forgotten to lock the door.
Quizá me haya olvidado de cerrar la puerta con llave.
Modal Verbs - Might
El verbo 'might' expresa débil probabilidad o posibilidad. Se utiliza
cuando queremos decir: podría, quizás, puede que (They might come
tomorrow).
I might - podría / quizás / puede que
Affirmative
They might be waiting for us at the station.
Podrían estar esperándonos en la estación.
This might be our only chance
Esta podría ser nuestra única oportunidad.
I might lose my job.
Podría perder mi trabajo.
Harry might write soon.
Harry podría escribir pronto.
You might find a solution.
Podrías encontrar una solución.
We might be going the wrong way.
Quizás estemos yendo en la dirección equivocada.
I might call you tomorrow.
Podría llamarte mañana.
Negative
Sylvia might not live there anymore.
Quizás Sylvia ya no viva más ahí.
We might not know everything.
Puede que no sepamos todo.
It might not rain tonight.
Puede que no llueva esta noche.
Interrogative
Might I give you a piece of advice?
¿Podría darte un consejo?
Might we speak to you for a moment?
¿Podríamos hablar contigo un momento?
Might + have
They might have finished earlier.
Quizás hayan terminado más temprano.
Bob might have died in the accident.
Bob podría haber muerto en el accidente.
Miss Green might not have been present at the time.
Puede que la señorita Green no haya estado presente en ese momento.
Modal Verbs - Must
El verbo 'must' expresa una prohibición u obligación fuerte así como
cierta certeza: I must go. She must be crazy. En español significa debo,
debo de.
I must - debo / debo de
Affirmative
I must go to the library.
Debo ir a la biblioteca.
You must stay here until I come back.
Debes quedarte aquí hasta que yo vuelva.
We must be at the airport at three o'clock.
Debemos estar en el aeropuerto a las tres.
Everybody must wear a uniform.
Todos deben usar uniforme.
You must be joking!
¡Deben de estar bromeando!
Julia must be in Paris by now.
Julia ya debe de estar en París.
It must be noon already.
Ya debe de ser mediodía.
Negative
You must not talk to strangers.
No debes hablar con extraños.
We mustn't make noise.
No debemos hacer ruido.
Mr. Williams must not smoke.
El señor Williams no debe fumar.
Interrogative
Must we do everything today?
¿Debemos hacer todo hoy?
Must you go so soon?
¿Debes irte tan pronto?
Must + have
I must have fallen asleep.
Debo de haberme quedado dormido.
Sally must have forgotten about the meeting.
Sally debe de haberse olvidado de la reunión.
They must have sent it already.
Ya deben de haberlo enviado.
Modal Verbs - Should
Usamos 'should' para expresar grado de posibilidad o probabilidad,
así como también para obligación débil. Significa: debería, tendría que.
I should study.
I should - debería / tendría que
Affirmative
You should tell Miss Baker the truth.
Deberías decirle la verdad a la señorita Baker.
We should go to sleep.
Deberíamos ir a dormir.
I should call my mother.
Debería llamar a mi madre.
They should leave as soon as possible.
Ellos deberían salir lo antes posible.
She should be doing her homework.
Ella debería estar haciendo su tarea.
Ben should exercise more.
Ben debería ejercitarse más.
It should be here.
(Esto) Debería estar aquí.
Negative
You should not say that.
No deberías decir eso.
Nick shouldn't be working.
Nick no debería estar trabajando.
It shouldn't take long.
(Esto) No debería tardar mucho.
Interrogative
Should I write Maggie a letter?
¿Debería yo escribirle una carta a Maggie?
Should we worry?
¿Deberíamos preocuparnos?
Should + have
Charlie should have consulted me.
Charlie debería haberme consultado.
I shouldn't have eaten so much.
Yo no debería haber comido tanto.
Danny and Paul should have waited for you.
Danny y Paul deberían haberte esperado.
Modal Verbs - Ought to
El verbo 'ought to' es igual al 'should' y expresa una obligación débil. Significa debería, tendría que.
I ought to - debería / tendría que
Affirmative
Helen ought to be more careful.
Helen debería tener más cuidado.
I ought to stay in bed.
Yo debería quedarme en la cama.
We ought to go together.
Deberíamos ir juntos.
They ought to be here already.
Ellos ya deberían estar aquí.
You ought to eat more vegetables.
Deberías comer más vegetales.
Tom ought to take her home.
Tom debería llevarla a casa.
It ought to work properly.
(Esto) Debería funcionar correctamente.
Negative
You ought not to drink so much.
No deberías beber tanto.
They ought not to go camping without a torch.
Ellos no deberían ir de camping sin una linterna.
George ought not to wear someone else's glasses.
George no debería usar los anteojos de otra persona.
Interrogative
Ought Rachel to be here so early?
¿Debería Rachel estar aquí tan temprano?
Ought they to live there?
¿Deberían ellos vivir allí?
Ought to + have
You ought to have read the book for today.
Deberían haber leído el libro para hoy.
They ought to have gone to the supermarket.
Ellos deberían haber ido al supermercado.
We ought to have listened to the guard.
Deberíamos haber escuchado al guardia.
Modal verbs
The modal verbs include can, must, may, might, will, would, should. They are used with other verbs to express ability, obligation, possibility, and so on. Below is a list showing the most useful modals and their most common meanings:
Modal
Meaning
Example
can
to express ability
I can speak a little Russian.
can
to request permission
Can I open the window?
may
to express possibility
I may be home late.
may
to request permission
May I sit down, please?
must
to express obligation
I must go now.
must
to express strong belief
She must be over 90 years old.
should
to give advice
You should stop smoking.
would
to request or offer
Would you like a cup of tea?
would
in if-sentences
If I were you, I would say sorry.
Modal verbs are unlike other verbs. They do not change their form (spelling) and they have no infinitive or participle (past/present). The modals must and can need substitute verbs to express obligation or ability in the different tenses. Here are some examples:
Past simple
Sorry I'm late. I had to finish my math test.
Present perfect
She's had to return to Korea at short notice.
Future
You'll have to work hard if you want to pass the exams.
Infinitive
I don't want to have to go.
Past simple
I couldn't/wasn't able to walk until I was 3 years old.
Present perfect
I haven't been able to solve this problem. Can you help?
Future
I'm not sure if I will be able to come to your party.
Infinitive
I would love to be able to play the piano.
Modals are auxiliary verbs. They do not need an additional auxiliary in negatives or questions. For example: Must I come? (Do I must come?), or: He shouldn't smoke (He doesn't should smoke).
Modals are different from normal verbs:
1: They don't use an 's' for the third person singular. 2: They make questions by inversion ('she can go' becomes 'can she go?'). 3: They are followed directly by the infinitive of another verb (without 'to').
Probability:
First, they can be used when we want to say how sure we are that something happened / is happening / will happen. We often call these 'modals of deduction' or 'speculation' or 'certainty' or 'probability'. For example:
It's snowing, so it must be very cold outside.
I don't know where John is. He could have missed the train.
This bill can't be right. £200 for two cups of coffee!
Modal Verbs of Probability
We can use these modal verbs (also called modals of deduction, speculation or certainty) when we want to make a guess about something. We choose the verb depending on how sure we are.
1: Talking about the present:
must / might / could / may / can't
must + infinitive
might / might not + infinitive
could / could not + infinitive
may / may not + infinitive
can't + infinitive
For example:
I am waiting for Julie with another friend, David. I ask: 'Where is Julie?' David guesses:
She must be on the bus. (I'm fairly sure this is a good guess)
She might come soon. (maybe)
She could be lost. (maybe)
She may be in the wrong room. (maybe)
She can't be at home. (I'm fairly sure this isn't true)
Notice that the opposite of 'must' is 'can't in this case.
Will / won't
We use will and won't when we are very sure:
She'll be at work now.
Should / shouldn't
Should and shouldn't are used to make an assumption about what is probably true, if everything is as we expect:
They should be there by now.
It shouldn't take long to drive here.
This use of should isn't usually used for negative events. Instead, it's a better idea to use will:
The underground will be very busy now (not: 'should be').
Can
Can is used for something that is generally possible, something we know sometimes happens:
Prices can be high in London.
Can is not used to talk about specific possibilities:
He could be on the bus (not: 'can be').
2: Using modal verbs to talk about the past:
must / might / could / may / can't + have + past participle
Will and won't / will not + have + past participle are used for past certainty (compare with present use of 'will' above):
The parcel will have arrived before now.
Should + have + past participle
Should + have + past participle can be used to make an assumption about something that has probably happened, if everything is as we expect (compare with present use of 'should' above):
The train should have left by now
Could
We can use could + infinitive to talk about a general possibility in the past (compare with the use of 'can' above):
Prices could be high in the sixteenth century.
This is not used to talk about specific possibilites in the past (instead we use could + have + past participle):
He could have been working late (not: 'could be'. As this is a specific possiblity, 'could be' is present tense)
Ability
We use 'can' and 'could' to talk about a skill or ability.
For example:
She can speak six languages.
My grandfather could play golf very well.
I can't drive.
When we talk about ability, we mean two things.
First, we mean general ability. This is something that once you have learned you can do any time you want, like being able to read or swim or speak a language, for example.
The other kind of ability is specific ability. This mean something that you can or can't do in one particular situation. For example, being able to lift something heavy, or find somewhere you are looking for.
Present:
can / can't (for both general and specific ability)
I can play the piano.
She can speak English.
He can't drive – he's too tired.
We can't come now.
Past:
could / couldn't (for general ability)
I could read when I was four.
She could speak French when she was a child, but now she has forgotten it.
He couldn't dance at all until he took lessons.
My grandfather couldn't swim.
was able to / couldn't (for specific ability)
When the computer crashed yesterday, I was able to fix it.(not 'I could fix it')
She was able to pass the exam, even though she hadn't studied much.(not 'she could pass')
He called us because he couldn't find the house.
I couldn't open the window.
could + have + past participle (an ability someone had in the past, but didn't use)
I could have played the piano well but I didn't practise enough.
We could have come earlier.
She could have studied law, but she preferred to become a secretary.
Future:
will / won't be able to (general ability)
At the end of the course, you will be able to make your own website.
He won't be able to speak Japanese in a week! It will take months.
can / can't (specific ability)
I can help you tomorrow
I can't come to the party
Obligation and Advice
We can use verbs such as 'must' or 'should' to say when something is necessary or unnecessary, or to give advice.
For example:
Children must do their homework.
We have to wear a uniform at work.
You should stop smoking.
We can use have to + infinitive, must + infinitive and should + infinitive to express obligation (something you have to do).
Present
Positive
Negative
have to / don't have to
strong obligation (possibly from outside)
Children have to go to school.
(sometimes 'have got to')
no obligation
I don't have to work on Sundays.
You don't have to eat anything you don't like.
must / mustn't
strong obligation (possibly based on the speaker's opinion)
I must study today.
negative obligation
You mustn't smoke here.
should / shouldn't
mild obligation or advice
You should save some money.
mild negative obligation or advice
You shouldn't smoke so much.
Be careful about the difference between mustn't and don't have to! Mustn't means it's not allowed, or it's a bad idea:
You mustn't eat so much chocolate, you'll be sick
Don't have to means you don't need to do something, but it's fine if you want to do it:
I don't have to get up early at the weekend(of course, if I want to get up early, that's fine, but I can stay in bed if I want).
Past
Positive
Negative
had to / didn't have to
obligation in the past
I had to wear a school uniform when I was a child.
no obligation in the past
We didn't have to go to school on Saturdays.
must*
changes to 'had to'
-
should have + pp / shouldn't have + pp
a past action which didn't happen: the advice / regret is too late
You should have gone to bed earlier, now you have missed the train.
a past action which didn't happen: the advice / regret is too late
You shouldn't have taken that job., it was a bad idea.
* Remember 'must have done' is a modal verb of deduction or speculation, not obligation in the past. For example: Julie must have left. Her coat's not here.
Permission
We can use verbs such as 'can', 'could' and 'may' to ask for and give permission. We also use modal verbs to say something is not allowed.
For example:
Could I leave early today, please?
You may not use the car tonight.
Can we swim in the lake?
Habits
We can use 'will' and 'would' to talk about habits or things we usually do, or did in the past.
For example:
When I lived in Italy, we would often eat in the restaurant next to my flat.
John will always be late!
Past modals
The past modals 'could have + past participle', 'should have + past participle' and 'would have + past participle' can be confusing.
Could have, should have, would have
These past modal verbs are all used hypothetically, to talk about things that didn't really happen in the past.
Could have + past participle
1: Could have + past participle means that something was possible in the past, or you had the ability to do something in the past, but that you didn't do it.
I could have stayed up late, but I decided to go to bed early.
They could have won the race, but they didn't try hard enough.
Julie could have bought the book, but she borrowed it from the library instead.
He could have studied harder, but he was too lazy and that's why he failed the exam.
Couldn't have + past participle means that something wasn't possible in the past, even if you had wanted to do it.
I couldn't have arrived any earlier. There was a terrible traffic jam (= it was impossible for me to have arrived any earlier).
He couldn't have passed the exam, even if he had studied harder. It's a really, really difficult exam.
2: We use could have + past participle when we want to make a guess about something that happened in the past. In this case, we don't know if what we're saying is true or not true. We're just talking about our opinion of what maybe happened.
Why is John late?
He could have got stuck in traffic.
He could have forgotten that we were meeting today.
He could have overslept.
We can also choose to use might have + past participle to mean the same thing:
He might have got stuck in traffic.
He might have forgotten that we were meeting today.
He might have got stuck in traffic.
Should have + past participle
1: Should have + past participle can mean something that would have been a good idea, but that you didn't do it. It's like giving advice about the past when you say it to someone else, or regretting what you did or didn't do when you're talking about yourself.
Shouldn't have + past participle means that something wasn't a good idea, but you did it anyway.
I should have studied harder! (= I didn't study very hard and so I failed the exam. I'm sorry about this now.)
I should have gone to bed early (= I didn't go to bed early and now I'm tired).
I shouldn't have eaten so much cake! (= I did eat a lot of cake and now I don't feel good.)
You should have called me when you arrived (= you didn't call me and I was worried. I wish that you had called me).
John should have left early, then he wouldn't have missed the plane (= but he didn't leave early and so he did miss the plane).
2: We can also use should have + past participle to talk about something that, if everything is normal and okay, we think has already happened. But we're not certain that everything is fine, so we use 'should have' and not the present perfect or past simple. It's often used with 'by now'.
His plane should have arrived by now (= if everything is fine, the plane has arrived).
John should have finished work by now (= if everything is normal, John has finished work).
We can also use this to talk about something that would have happened if everything was fine, but hasn't happened.
Lucy should have arrived by now, but she hasn't.
Would have + past participle
1: Part of the third conditional.
If I had had enough money, I would have bought a car (but I didn't have enough money, so I didn't buy a car).
The Third Conditional
We make the third conditional by using the past perfect after 'if' and then 'would have' and thepast participle in the second part of the sentence:
if + past perfect, ...would + have + past participle
It talks about the past. It's used to describe a situation that didn't happen, and to imagine the result of this situation.
If she had studied, she would have passed the exam (but, really we know she didn't study and so she didn't pass)
If I hadn't eaten so much, I wouldn't have felt sick (but I did eat a lot, and so I did feel sick).
If we had taken a taxi, we wouldn't have missed the plane
She wouldn't have been tired if she had gone to bed earlier
She would have become a teacher if she had gone to university
He would have been on time for the interview if he had left the house at nine
2: Because 'would' (and will) can also be used to show if you want to do something or not (volition), we can also use would have + past participle to talk about something you wanted to do but didn't. This is very similar to the third conditional, but we don't need an 'if clause'.
I would have gone to the party, but I was really busy. (= I wanted to go to the party, but I didn't because I was busy. If I hadn't been so busy, I would have gone to the party.)
I would have called you, but I didn't know your number. (= I wanted to call you but I didn't know your number, so I didn't call you.)
A: Nobody volunteered to help us with the fair B: I would have helped you. I didn't know you needed help. (= If I had known that you needed help, I would have helped you.)
