Indefinite articles - a and an
A and an are the indefinite articles. They refer to something not specifically known to the
person you are communicating with.
1) Before countable nouns that introduce something or someone you have not mentioned before
e.g.: I saw an elephant this morning.
I ate a banana for lunch
2) When talking about your profession:
e.g.: I am an English teacher."
I am a builder
3) When defining a type of objects / beings; for example, when we answer the question: "What's a lion?"
e.g.: A lion is a wild animal
- You use a when the noun you are referring to begins with a consonant (b, c, d, f, g, h, j, k, l, m, n, p, q, r, s, t, v, w, x, y or z), for example, "a city", "a factory", and "a hotel".
- You use an when the noun you are referring to begins with a vowel (a, e, i, o, u)
Pronunciation changes this rule. It's the sound that matters, not the spelling. If the next word begins with a consonant sound when we say it, for example, "university" then we use a. If the next word begins with a vowel sound when we say it, for example "hour" then we use an.
We say "university" with a "y" sound at the beginning as though it were spelt "youniversity". So, "a university" IS correct.
We say "hour" with a silent h as though it were spelt "our". So, "an hour" IS correct.
Definite articles - the
There are two ways to pronounce "the". One "thuh" and the other "thee". To learn when we use them see the pronunciation files: How to pronounce "the".
1) When you know that the listener knows or can work out what particular person/thing you are talking about
e.g.: The apple you ate was rotten.
Did you lock the car?
2) When you have already mentioned the thing you are talking about.
e.g.: She's got two children; a girl and a boy. The girl's eight and the boy's fourteen.
3) With some uncountable nouns, which do not have a plural form:
e.g.: Jack is ill today. He’s got the flu.
Where is the luggage?
3) To talk about geographical points on the globe.
e.g.: the North Pole, the Equator
4) To talk about rivers, oceans and seas
e.g.: the Nile, the Pacific, the English Channel
5) Before certain nouns when we know there is only one
of a particular thing
e.g.: the rain, the sun, the wind, the world, the Earth, the White House etc.
However if you want to describe a particular instance of these, you should use a/an.
e.g.: I could hear the wind." / "There's a cold wind blowing
What are your plans for the future?" / "She has a promising future ahead of her.
The doesn't mean all
e.g.: The books are expensive." = (Not all books are expensive, just the ones I'm talking about.
Books are expensive." = (All books are expensive.)
We usually use no article:
1) To talk about things in general:
e.g.: Inflation is rising.
People are worried about rising crime. (Note! People generally, so no article)
2) When talking about sports.
e.g.: My son plays football.
Tennis is expensive
3) When talking about times and dates:
a. Days of the week:
e.g.: I don't work on Thusdays
b. Periods of time such as the previous / the following weekend, year, month, season...
e.g.: Last weekend I went shopping
The course begins next week
I went to Austria last winter
See you on Thursday
But we DO use the in these contexts:
Nineteen sixty-eight was the last year they made that car.
We usually go on vacation the week after Christmas.
4) When talking about quantities and proportions:
a. Using most referring to "the majority of"
e.g.: Most people think the president is guilty
b. With quantities and percentages:
e.g.: Half of my students never do the homework
Eighty percent of those houses were built in the last ten years
5) We do not use the to talk about places such as home, school, prison, work, church, bed; except if it is a specific example.
e.g.: When I was at school we didn’t use computers.
She’s not at home right now; she’s at school.
He’s in bed.
I’m at work.
He's in prison, in hospital...
The school I went to was built in the nineteenth century.
The schools in that neighborhood aren’t very good.
6) Before the names of countries except where they indicate multiple areas or contain
the words (state(s), kindom, republic, union). Kingdom, state, republic and union are nouns, so they need an article.
e.g.: No article - Italy, Mexico, Bolivia, England
Use the - the UK (United Kingdom), the USA (United States of America), the Irish Republic
Multiple areas - the Netherlands, the Philippines, the British Isles
BE CAREFUL: Many Spanish speaking people use the article when using the possessive with a proper noun:
the Aznar’s moustache X –> Aznar’s moustache :
Do you like the John’s new haircut? X –> Do you like John’s new haircut? :)
the Dracula's castle X –> Dracula's castle :)
http://www.hablamejoringles.com/articulo-sobre-articulos-el-uso-de-the-en-ingles/ (activities at the end)