Grammatical agreement means that units of a sentence (such as subject and verb) use the same form to show number, person, gender, or case. (See agreement of pronouns and antecedents and agreement of subjects and verbs.)
agreement of pronouns and antecedents
Gender and Number
Compound and Collective Antecedents
Every pronoun must have a clear antecedent, a noun (or sometimes another pronoun) to which it unmistakably refers.
Studs and thick treads make snow tires effective. They are implanted with an air gun. [Unclear; Which are implanted with an'air gun, studs or thick treads?]
The antiquated heating system has resulted in an equipment failure.
Ihis is our most serious problem at present. [Unclear: Which is our most serious problem at present, the antiquated heating system or the equipment failure? The correction assumes that the writer meant This to refer to the heating system.]
Using the relative pronoun which to refer to a whole clause instead of to a specific noun can be confusing.
change Fred acted independently on the advice of his consultant, which the others thought was wrong. [Unclear: Was the fact that Fred acted independently or was the consultants advice what the others thought was wrong?]
to The others thought that Fred's acting independently, which he did on the advice of his consultant, was wrong. [Which now clearly refers to Fred's acting independently]
or The others thought that the consultant's advice to act independently, which Fred followed, was wrong. [It is now clear that the consultant's advice is what the others thought was wrong.]
or Fred acted independently on the advice of his consultant, much to the distress of the others.
or The others thought that Fred's acting independently on his consultant's advice was wrong.
[Both of the last two examples are acceptable solutions if the writer does not wish to emphasize either the advice or the acting independently as the source of the others' disapproval but wishes to emphasize the whole idea of Fred's acting independently on his consultant's advice.]
GENDER AND NUMBER
A pronoun must agree with its antecedent in gender (masculine, feminine, or neuter).
Mr. Swivet acknowledges his share of the responsibility, just as Mrs. Barkley must acknowledge hers.
Traditionally, a masculine, singular pronoun has been used with singular antecedents whose gender is indefinite, such as anyone, everyone, person, and each. However, many people are now offended by an implied sexist bias in such usage. Unless a sentence is clearly being used in an allVmale or all-female context (in which case he or she may be the accurate choice), revise it to include both genders. (See also nonsexist language.)
Inclusiveness can be achieved in several ways. Rephrase a sentence to eliminate the gender-specific pronoun entirely.
change Each may go as he chooses.
to Each may choose whether to stay or go.
or Each is free to stay or go.
Use both feminine and masculine pronouns. (However, this device can become wordy and awkward if used too often.)
Each may stay or go as he or she chooses.
If appropriate, use the second-person pronoun you, which is the same for both genders.
You may each stay or go as you choose.
Change a gender-specific singular pronoun (he or she) to the plural they, which is not gender specific. Caution: The antecedent of they must also be changed to the plural; do not attempt to avoid expressing gender by resorting to a plural pronoun when the antecedent is singular (see the discussion of number that follows).
They all may stay or go as they choose.
or They each may stay or go as they choose.
but not Each may stay or go as they choose. [Each is singular; they is plural.]
A pronoun must agree with its antecedent in number (singular or plural).
Every employee must sign their (his or her) time card.
OR
Every (all) employee(s) must sign their time card(s).
Use singular pronouns with the antecedents everybody, everyone, anyone, each, either, neither, sort, and kind unless to do so would be illogical because the meaning is obviously plural. (See also everybody / everyone.)
Everyone pulled their (hisor her) share of the load, [if persons of both genders are involved]
Everyone pulled their share of the load. [only in an all-male context]
Everyone pulled their share of the load, [only in an all-female context]
Everyone pulled an equal share of the load, [rephrased to eliminate the plural pronoun their]
The pronouns everyone and everybody, which are formally singular, occasionally have a meaning so obviously plural that no revision to achieve agreement in number seems a real improvement. This situation is especially likely to occur when the plural pronoun they or their refers to an antecedent everyone or everybody in a previous independent clause or sentence.
Everyone laughed at my bad haircut, and I really couldn't blame them. [Here, them cannot logically be changed to him or her]
Depending on the context, possibly Everyone could be changed to a plural form.
Everyone (All the guests )laughed at my bad haircut, and 1 really couldn't blame them.
Another solution is to change the second clause to eliminate the plural pronoun entirely.
Everyone laughed at my bad haircut, and I really couldn't blame them (had to agree).
Not all readers would object to the original sentence, but some surely would. Perhaps the best advice is to know your readers and, if in doubt, revise. This policy may be especially sensible in a writing course; usually even the most liberal instructors want to be sure that students understand grammatical principles before they bend the rules.
COMPOUND AND COLLECTIVE ANTECEDENTS
A compound antecedent with its elements joined by and requires a plural pronoun.
Martha and Joan took their briefcases with them.
If both antecedents refer to the same person, however, use a singular pronoun.
The respected economist and author departed from her prepared speech.
A compound antecedent joined by or or nor is singular if both elements are singular and is plural if both elements are plural.
Neither the cook nor the waiter could do his job until he understood the new computer system.
Neither the coaches nor the players were pleased by the performance of their team.
When one of the antecedents connected by or or nor is singular and the other plural, the pronoun agrees with the nearer antecedent. Often, however, the result is awkward and the sentence should be rewritten.
Either the supervisor or the operators will have their licenses suspended, [grammatically correct but at least slightly awkward]
Either the operators or the supervisor will have his license suspended, [grammatically correct but very awkward]
The licenses of either the operators or the supervisor will be suspended, [rewritten to reduce awkwardness]
Collective nouns may be singular or plural, depending on meaning.
The eommittee adjourned only after if had deliberated for days.
The committee quit for the day and went to their homes.