Singular and plural
This category refers to problems with number – especially to instances in which “s” has either been omitted or should be added to a word.
** THERE ARE TWO MAIN TYPES OF NUMBER PROBLEMS:
1. A NOUN IS SINGULAR AND SHOULD BE PLURAL.
Ex. At time, (A) a prime minister can bring a country (B) together and lead (C) it in a new direction. (D)
In this example, A is incorrect, “time” should be “times”.
2. A NOUN IS PLURAL AND SHOULD BE SINGULAR.
Ex. Before running a marathon, (A) a runner (B) must be sure that there is a steady supply of waters (C) on hand. (D)
In this example, D is incorrect, “waters” should be “water”.
Ex. That human beings (A) need oxygens (B) in order to survive is a self-evident (C) fact (D).
In this example, B is incorrect, “oxygens” should be “oxygen”.