Hi Ezzat! I'll do my best to explain but I don't think there are set rules for this particular quirk... "The" and "a/an" are definite and indefinite articles. No article is used in the following cases: - When referring to general ideas, plurals or uncountable nouns. E.G. --> "Mexican food is spicy" (NOT "The Mexican food is spicy.") - Names of people, books and plays (unless it is part of the title). E.G. --> "I have read Romeo and Juliet." - Towns, cities, states and countries. E.G. "Australia," "Tokyo," "China." (Exceptions – The USA, The UK, The Netherlands, The Czech Republic, The Philippines). - Sports or games. E.G. --> "soccer," "tennis," or "chess." - Meals. E.G. --> "breakfast," "lunch," and "dinner" In addition, the "a/an" indefinite article is not used with possessive pronouns, demonstratives or cardinal numbers. "My shirt is dirty." "This car is expensive." "One person is in the reception." Use "one" (or whichever quantity of thing you're referring to) instead of "a/an" when the number is important. "There is only one exit from the airport." I hope that helps!

The following are some of the most important guidelines with example sentences for the use of articles: - You use an uncount noun with no article if you mean all or any of that thing. Example: I don't eat cheese. - You use 'the' with an uncount noun when you are talking about a particular example of that thing. Example: I didn't eat the cheese. - You usually use 'a' or 'an' with a count noun the first time you say or write that noun. Example: There's a dog in the river! - You use 'the' with count nouns the second and subsequent times you use the noun, or when the listener already knows what you are referring to (maybe because there is only one of that thing). Example: Where's the pen I lent you yesterday? - You use a plural count noun with no article if you mean all or any of that thing. Example: I don't like cats. Note: Some nouns can be either count or uncount, depending on the context and meaning: Do you have paper? I want to draw a picture. (uncount = a sheet of paper) Can you get me a paper when you're at the shop? (count = a newspaper) Uncount nouns are usually preceded by phrases such as a lot of...(luck), a piece of...(cake), a bottle of....(milk), a grain of...(rice).