Quantifiers (1): Articles -- A, An, The

Article is, basically, an adjective which is used to modify noun. “A” or “An” is called indefinite article; “The” is called definite article. 

[1]   USING DEFINITE ARTICLES: A / AN

"A/An" is used with singular countable nouns only. The common use are: 

1.1. Things in general or unspecified things (something not specifically known to the person you are communicating with; or about any of the group)

"A" + words beginning with a consonant SOUND

For examples,

• a box, a book, a cat, a table, a school…
• a horse, a house, a hotel…. (begin with a consonant sound)
• a university, a user, a unicorn, a European trip… (begin with a consonant sound)

"An" + words beginning in a vowel SOUND or with a "silent h"

For examples, 

• an apple, an umbrella, an atom, an entrance, an ice cream cone, an uncle… 
• an hour, an honest man, an honorable guest … (the h is silent, thus a vowel sound)

1.2. First mention (to mention something for the first time or introduce something or someone you have not mentioned before.)

For examples, 

• I saw an elephant this morning…. (If we mention it, elephant again, we use "the")
• I ate a banana for lunch.

1.3.  Membership in a profession, nation, or religion

For examples,

• I am a teacher.
• She is an engineer.
• Thomas is a banker.

1.4.  Expression of measurement (time, quantity, and number)

For examples, 

• three times a week, 
• 50 km an hour, 
• $0.50 a kilo, 
• $480 a year…

[2]   USING DEFINITE ARTICLE: THE

"The" is used with both countable and uncountable nouns. The common uses are:

2.1. Specified or particular things 

The listener knows or can work out what particular person/thing you are talking about; or bout a particular member of a group.

For examples, 

• "The apple you ate was rotten." (Speaker/listener knows which apple it is.)
• "Did you lock the car?"

2.2.  Subsequent mentions

Second mention (when you have already mentioned the thing you are talking about.)

For examples, 

• She's got two children; a girl and a boy. The girl's eight and the boy's fourteen.
• I found a good handout on English articles. The handout is available online.

Second mention (with implied first mention—this one is very common)
 

For examples, 

• The dean called for a urgent college meeting. He said the teachers need internal policy training. ("the teachers" is implied by "college meeting "— every college meeting involves teachers.)
• My computer got an error. The files were lost. (Again, "the files" is implied by "computer error")

2.3. Unique things (we know that there is only one.)

For examples, 

• the rain, the sun, the wind, the world, the earth,...

Note: However if you want to describe a particular instance of these you should use a/an.

For examples, 

• "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."

2.4.  Names of Geographical areas

For examples,

• Rivers: the Nile, the Mekong, the Mississippi….
• Mountain ranges: the Dang Rek, the Andes, the Rocky, the Himalayan…
• Oceans, seas, and gulfs: the Pacific, the South China Sea, the Persian Gulf…
• Regions: the North Pole, the equator, the Amazon Forest, the Middle East, the West… 
• Countries (where they contain the words: state(s), kingdom, republic, union):  the USA, the Netherlands, the USSR, the Philippine, the UK…
• Deserts: the Sahara, the Kalahari…
• Group of islands/archipelago: the Maldives, the Andaman Islands, the Comoro Islands…
• Peninsulas: the Indochina Peninsula, the Scandinavia, the Balkan...

2.5.  Names of hotels, restaurants, pubs, cinemas, theatres, museums, galleries, newspapers, and organizations

For examples,

• The Cambodiana Hotel, The Raffle Hotel….
• The Cambodia Daily, The Kohsantepheap Daily…
• The National Museum, the S21 Museum…
• the United Nations, the ASEAN, the WTO…
• the Royal University of Agriculture, the National University of Management…

Note: but not the Norton University

2.6.  Ordinals and superlatives (first, next, primary, most, best, least, etc.)

For examples, 

• The first man to set foot on the moon…
• The greatest advances in medicine…

2.7.  Refer to the whole group or class or the national groups

For examples,

• The tiger is threatened with extinction.
• The French drink more wine than the English.
• the democrats, the conservatives…

2.8.  Before adjectives (to make it plural noun -- always plural.)

For examples, 

• the poor  [= the poor people]
• the unemployed/ the jobless  [=the unemployed people]
• the disabled [= the disabled people]

2.9.  Musical instruments, seasons

For examples,

• the piano, the flute, the drum….
• It’s very hot in the summer.

2.10.  Directions (north, south, east, west)
 

For examples, 

• Go to the south, then to the west!

[3]   USING ZERO ARTICLE: (Ø)            

3.1. Speaking about things generally

For examples,

• ø People are worried about rising crime. (Note! People generally, so no article)  
• ø Information is important to any organization. 
• ø Intelligence is difficult to quantify.

3.2. Sports
 
For examples, 

• My son plays ø football/ø volleyball /ø hockey /ø baseball.
• ø Tennis is expensive.

3.3. Academic subjects

For examples,

• ø mathematics, ø biology , ø history , ø computer science …

3.4. Languages and nationalities

For examples, 

• ø Chinese, ø English, ø Spanish, ø Russian …

3.5. Countries, states, cities or towns

For examples, 

• ø Italy, ø Mexico, ø Bolivia, ø Peru… (except: the UK, the US…)
• ø Texas, California, Oregon…
• ø Phnom Penh, ø Seoul, ø Miami….

3.6. Meals, places, and transport

For examples,

• He has ø breakfast at home. (but, He has a lovely breakfast.)
• I go to ø university.
• He comes to work by ø taxi.

3.7. Streets

For examples, 

• ø Norodom Blvd, ø Preah Sihanouk Avenue…

3.8. Lakes, mountains, continents, and islands
 
For examples,

• Lakes: ø Tonle Sap Lake, ø Lake Bikal, ø Lake Erie … 
• Mountains: ø Mount Everest, ø Mount Fuji, … 
• Continents: ø Asia, ø Europe, ø Africa, ø America, and ø Antarctica 
• Islands: ø Easter Island, ø Reusey Island……….

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