Many students find the use of the article in english confusing. Part of the reason for this confusion is that there are general rules as well as a number of exceptions to the rules.
We use the indefinite articles, “a” and “an,” to refer to an item (a single countable noun) that is not specifically identified.
Use “a” before words beginning with a consonant sound:
*Note: If the “u” sound is pronounced “uh,” as in “uncle,” “umbrella,” and “upsetting,” then it is preceded by “an.” However, if it is pronounced “yuh” as in “university,” “unique,” and “universal” then it is preceded by “a.” Similarly, when “o” is pronounced “wha,” as in “once,” then it too is preceded by “a” rather than “an.”
We use the definite article, “the,” to refer to a specific item (a countable noun) that both speaker and listener know: Can I borrow the pen that’s on your desk? (I have identified exactly which pen I want.)
We use no article before a plural countable noun: I borrowed pens from all my classmates.
We use no article before uncountable nouns when the meaning is general: Love is hard to define.
We use the definite article, “the,” when the noun becomes specific: The love of a mother for her child is revered all over the world.