1) We usually use a/an to classify people or things when we mention them first
We read a story about a man, a young Irish girl and a priceless diamond ring.
2) We use a/an when we classify the kind of thing we are talking about
What’s this? It a mouse.
3) We use a/an when we talk about any example of the kind of thing we are talking about.
Do you have a ruler? I’m looking for a knife.
4) We use a/an when we classify people by the work they do
I’m a socialist, not a communist.
5) We use a/an when we classify things in definitions.
A dolphin isn’t’ a fish, it’s a mammal.
6) We use a/an in descriptions of particular features
The professor had a big nose, a small mouth, an enormous moustache.
7) We use a/an with a proper noun for one example of the type of thing mentioned.
That painting is a Picasso. Is your watch a Calvin Klein?
8) We use a/an or one before a noun to talk about a single thing or person.
In some places, there are graves that are used again after one/a year and one/a day.
9) We use one to emphasize the number (only one or just one) and to talk about a particular but unspecified occasion, usually in narrative
We only have room for one passenger
One day there was a terrible storm.
10) We use one in exact numbers, especially in phrases with larger numbers.
Our first car cost one thousand, one hundred and twenty pounds.
11) We use a/an in approximate amounts and fractions.
That trip cost almost a hundred pounds.
1) We use “the” to identify people or things when we think they are already known
Do you remember the story about the man who tried to steal the ring from the Irish girl.
2) We use “the” when we assume that people are familiar with the same ordinary thing as we are in our daily lives.
Where’s the phone? I left it beside the radio on the table in the corner near the window.
3) We use “the” when we assume that people are familiar with the physical world outside.
Please don’t mention the sun, the sky, the earth, the weather, or the environment today.
4) We use “the” when we identify already known people by their jobs
Will you wait for the plumber? – I can’t. I have to go to the dentist.
5) We use “the” when we identify people by their unique roles in society.
Would you recognize the Pope, the Emperor of Japan, the Dalai Lama or the Queen?
6) We use “the” with professional organizations.
He’s thinking about joining the police or the army, his brother works for the government.
7) We use “the” when we talk about smth as a general concept and not referring to a specific example. We do this with inventions and musical instruments, people things and animals in generalization.
Can anyone here play the piano or the organ?
The horse was a symbol of freedom to the Apache. The customer isn’t always right.
8) We use “the” when we identify things or parts of things with descriptive prepositional phrases with of.
It’s the middle of June already and I haven’t’ finished painting the front of my house.
9) We use “the” when we identify things or parts of things with relative clauses
The person who called yesterday said you owned him 20 $.
10) We use “the” with emphasizing adjectives such as main.
That was the main reason for going early.
11) We use “the” with nouns such as history and poetry when they are followed by of-phrases and no article in other contexts.
The poetry of Philip Larkin is unusual. Poetry isn’t their favorite subject.
12) We use “the” with nouns to talk about a specific time or place, and no article with those same nouns after the prepositions in or at when we are talking mo generally.
a) After you pass the school, you’ll see the church. That was the Christmas before you were born.
b) Most people would rather be in school or in church.
13) We use no article when we talk about sports, in many prepositional phrases referring to general concepts
a) They came by bus.
14) We express associated information with ‘the’ and a different noun. In most cases the connection is between two nouns, based on common knowledge (a house has usually a kitchen)
a) We were thinking of buying a house in Wimbledon , but the kitchen was too small.
b) Luckily there was a taxi available and the driver spoke English
c) She has written a new book. I can’t remember the title. The cover is red with gold letters.
15) In some cases. The connection is between a verb and a noun
a) I really liked it, but I didn’t buy it because the price was too high.
b) He asked me about you. There was something odd about the tone of the question.
c) I worked there for a while but the pay was terrible.
16) We can use ‘the’ in a condensed way with a compound noun.. We can combine elements of information from one or more sentences to form the compound noun.
a) You have to fill out a form to apply for a credit card. The credit card application form actually represents a contract.