Page 125 - Advanced English Grammar in Use

T h e a n d a / a n ( 2 ) : ' t h i n g s a l r e a d y k n o w n ' , e t c .

We use the when we expect the listener or reader to be able to identify the thing or person we
are talking about, and we use a/an when we don't. Compare these pairs of sentences:
• Helen's just bought a house in Wilson Street, and
• Helen's just bought the house in Wilson Street. (= the house for sale we have previously
talked about)
• A Korean student in our class has had to go home, and
• The Korean student has had to go home. (= the Korean student we have previously talked
about)
• There's a bus coming, and
• The bus is coming. (= it's the bus we are waiting for)
• There's a woman from the bank on the phone, and
• He's in a meeting with the woman from the bank. (= you know which woman I mean)

r D We also use the when it is clear from the situation which person or thing we mean:
• What do you think of the table? (= the table we are looking at)
• This tastes lovely. What's in the sauce? (= the sauce here on my plate)
• The tree looks beautiful now that it's spring. (= the tree here in the garden)

Study these examples:
• Dorothy took a cake and an apple pie to the party, but only the apple pie was eaten.
We say 'an apple pie' when we first mention it, and 'the apple pie' after that, when the listener
or reader knows which apple pie we mean.
a • There was a serious fire in a block of flats in Glasgow last night. The building was totally
• destroyed.
We say 'a block of flats' when we first mention it. We use 'the building' because the listener (or
reader) will know which building we mean.
Even if the person or thing hasn't been mentioned before, if the person or thing we mean can be
understood from what has been said before, we use the:
• We had a good time on holiday. The hotel (= the hotel we stayed in) was comfortable, and
the beach (= the beach we went to) was only ten minutes away.
Notice that fictional writing (novels, short stories, etc.) will often mention something for the first
time with the to build up suspense, expectation, etc. For example, a story might begin:
• The woman opened the gate and looked thoughtfully at the house.

The is often used with nouns before a phrase beginning of.... The of... phrase connects this noun
to a particular thing or person:
• Pictures can help students learn the meaning of new words.
• The disease could have killed off half the population of the country.
• He was woken up by the sound of gunfire.
Compare these sentences with:
• Each new word has a different meaning.
• The country has a rapidly expanding population.
• He suddenly heard a sound like a gunshot.
Some nouns are commonly used in the pattern the...of... to refer to a particular place, time, etc.,
including back, beginning, bottom, end, middle, side, top:
• In the middle of his speech he started to cough uncontrollably.

The and a/an (1) = More on articles: