There are two kinds of articles: definite and indefinite. The definite article (the) can be singular or plural. The indefinite article (a or an) is singular, and cannot be used with a plural noun.

 A, An, The: General or Specific Use
 When to Use 'A,' 'An,' or 'The'
Articles Exercises
 Articles: Practice Sentences
 Articles: At the Party
 Articles: Laptops
 Articles: The Coffin Door
 Articles: Eggs and Pancakes
 Articles: Jane Met Boys
 Articles: Joe's Day at Gallaudet
 Articles: Laptop Cloze
 Articles: Student Responsibilities
 Articles: Snow??
Links on Articles
 The Use and Non-Use of Articles (Ohio State University)