TYPICAL ERROR The shark is the terror of many swimmers because they can attack swimmers even in shallow water.
CORRECTION The shark is the terror of many swimmers because it can attack swimmers even in shallow water.
EXPLANATION The word shark refers to only one thing (a single thing), so we say that its number is singular. To be logical, any pronoun that is used to refer to shark should also be singular. Thus, the word shark can be replaced by the pronoun it, which is singular, but not by the pronoun they, which is plural. Conversely, plural nouns such as sharks should be replaced by plural pronouns. Thus, we can say:
- The shark is the terror... because it attacks ... OR
- Sharks are the terror ... because they attack...
In these sentences, pronouns need changing so that they are the same number as the nouns to which they refer. Rewrite the sentences to make the sentences consistent throughout.