There has been an error in the display of this page. There has been an error in the display of the nav on this page. Click on an exercise title to enter the exercise page. Exercise 1: When to use singular and plural nouns Exercise 2: Using possessive endings correctly Exercise 3: Making pronouns and nouns agree Exercise 4: When to use a/an or no article Exercise 5: When to use a/an or the Exercise 6: When to use the or no article with plural or noncount nouns There has been an error in the display of this page.