2. MAKE PRONOUNS AND ANTECEDENTS AGREE

A pronoun is a word which refers to a subject or object which has already been identified. The antecedent is the word which is being referred to by the pronoun. For example: "When you use an antecedent in the first clause of a sentence, you can refer to it with the pronoun ‘it' in the second clause of the sentence." Pronouns are great things, as speech would be unbelievably tedious without them. Pronouns must, however, agree with their antecedents in number and gender, and many people are not careful enough about this. The most common error is to use the pronoun "they" to refer to a singular antecedent. Bad: "If you go and talk to a grammarian, they will say that you are dead wrong when you use ‘they' as a singular antecedent."

Many people make the foregoing mistake because they do not wish to use a gender-specific pronoun. We do not have a gender-neutral pronoun in English, so when we refer to an antecedent whose gender is unknown we must either use the old method and use "he" or we must say "he or she." Some people recommend alternating "he" and "she" as gender-neutral pronouns within a piece of writing, but we think this is rather contrived. (When feeling trendy, we use "(s)he," but we have heard this horrifies old school grammarians, so do so at your own risk.)

To use "they" with a singular antecedent is simply incorrect, because it does not agree in number with the noun to which it refers.

Wrong

"If you meet a snake-charmer on the road, tell them that you'll have none of their nonsense."

"I spoke to somebody at the office, but they couldn't help."

Right

"If you meet a snake-charmer on the road, tell him or her that you'll have none of his or her nonsense."

"I spoke to somebody at the office, but she couldn't help."

(In the latter case, since the writer spoke to the "somebody," the gender is probably known and therefore it should be specified.)