4. The words a/an and the are "articles". We divide them into "indefinite" and "definite" like this: We use "indefinite" to mean not sure, not certain. "Indefinite" is general. When we are talking about one thing in general, we use a or an. When we are talking about one thing in particular, we use the. indefinite articlesdefinite article a an the

5. Of course, often we can use a/an or the for the same word. It depends on the situation, not the word. Look at these examples: Example 1:We want to buy an umbrella. (Any umbrella, not a particular umbrella.) Example 2:Where is the umbrella? (We already have an umbrella. We are looking for our umbrella, a particular umbrella.)

6. 1- a = indefinite article (not a specific object, one of a number of the same objects) with consonants a + singular noun beginning with a consonant: Example: a boy; a car; a bike; a zoo; a dog 2- an = indefinite article (not a specific object, one of a number of the same objects) with vowels (a, e, I, o, u) or unvoiced consonant.= indefinite article an + singular noun beginning with a vowel: Example: an elephant; an egg; an apple; an idiot; an orphan 3- the = definite article (a specific object that both the person speaking and the listener know) that is identified as particular item(s). Example: "The dog that bit me ran away." Here, we're talking about a specific dog, the dog that bit me.

7. The form ‘a’ is used before consonant sounds and the form ‘an’ is used before vowel sounds. Example 1: a horse / a unit / a girl Example 2: an hour / an apple / an umbrella ‘a’ and ‘an’ is used before countable or singular noun referring to people or things that have already mentioned. Example 1: I can see a bird in the sky. Example 2: Mrs Amini is a clerk.

8. ‘a’ and ‘an’ are used before countable nouns when these have an adjective in front of them, or phrase following them. Example 1: He has a good knowledge of Spanish. Example 2: Mrs Jordan is a respectful person. ‘a’ and ‘an’ are used to show that sb/sth is member of a group or profession. Example: Smiths’ new car is a BMW.

9. ‘a’ and ‘an’ is used instead of one before some numbers. Example: A thousand people were killed in the earthquake. ‘a’ and ‘an’ is used before the names of days of the week to talk about one particular day. Example: I saw him on a Wednesday.

10.  We use ‘a’ and ‘an’ to classify people, animals, plants, … Example: an elephant is a big animal.  We use ‘a’ and ‘an’ with origins, occupations, religions, and politics Example 1: Sarah is a dentist. Example 2: Amir is an Iranian. Example 3: Mr Alavi is a socialist.

11.  We use ‘a’ and ‘an’ before a non-specific proper noun when he/she is unknown to us.(to show that the speaker does not know the person) Example: I am looking for a Miss Taheri.  We use ‘a’ and ‘an’ before measurements. Example: Ali studies English twice a week.

12.  ‘the’ is used to show that you are talking about a particular thing or person (singular, plural, or uncountable) that has already been mentioned, is already known about, or is the one. Example: I ordered a pizza and a salad. The pizza was nice and the salad was disgusting.  ‘the’ is used to refer sb/sth that is the only, normal and obvious one of their kind. Example: the Nile/ the Quran/ the Pacific ocean/ the Alps  ‘the’ is used to refer to o thing in general rather than a particular thing. Example 1: The dolphin is an intelligent animal. Example 2: I am usually out during the day.

13.  ‘the’ is used with adjectives to refer to a thing or group of people described by the adjective. Example : the unemployed / the elderly  ‘the’ is used before the plural of somebody ’s last name, refer to whole family, or married couple. Example : Do not forget to invite the Jordans.  ‘the’ is used with unit of measurement to mean “every”. Example : My car does 40 miles to the gallon.  ‘the’ is used with a unit of time to mean the “present”. Example : why do not have the dish of the day?

14.  ‘the’ is used to show that two things change to the same degree. Example 1: The less you talked about this matter, the more depressed she became. Example 2: The more I play volley ball, the happier I will be.  ‘the’ is used with the superlative form of comparison. Example: The city hall is the tallest building in town.  the’ is used with the word university or college comes before the name. Example 1: My brother is studying at the university of California. Example 2: My friend graduated from Tehran university.

15.  the’ is used with the words “past”, “present”, and “future” but not with the words “present time”, “past times”, and “future times”. Example 1: Ali has worked with the same firm from the time he was twenty to the present. Example 2: Undoubtedly there will be exciting new inventions in future times.  the’ is used before an “of-phrase”. Example: the leaves of trees in Autumn.  the’ is used with names of some countries. Example: the UAE/ the United Kingdom/ the Islamic Republic of Iran

16. There are some specific rules for using the with geographical nouns. Do not use ‘the’ before:  names of most countries/territories: Example: Italy, Mexico, Bolivia; however, the Netherlands, the Dominican Republic, the Philippines, the United States  names of cities, towns, or states: Example: Seoul, Manitoba, Miami  names of streets: Example: Washington Blvd., Main St.

17.  names of lakes and bays: Example: Lake Titicaca, Lake Erie except with a group of lakes like the Great Lakes  names of mountains: Example: Mount Everest, Mount Fuji except with ranges of mountains like the Andes or the Rockies or unusual names like the Matterhorn  names of continents Example: Asia, Europe  names of islands Example: Easter Island, Maui, Key West except with island chains like the Aleutians, the Hebrides, or the Canary Islands

18. Do use ‘the’ before:  names of rivers, oceans and seas: Example: the Nile, the Pacific  points on the globe: Example: the Equator, the North Pole  geographical areas: Example: the Middle East, the West  deserts, forests, gulfs, and peninsulas: Example: the Sahara, the Persian Gulf, the Black Forest, the Iberian Peninsula

19.  Bagheri, Mohamad Sadegh.(2011), Grammar Booster, Shiraz  Anderson, Trudy.(1950), English grammar digest  Oxford, advanced learner dictionary  Longman, advanced learner dictionary

20.  www.englishclub.com www.englishclub.com  www.esl.about.com www.esl.about.com  www.owl.english.purdue.edu www.owl.english.purdue.edu