Part of why subject/verb agreement errors are so numerous is because of the “special cases” that often arise in English, e.g., when words including “everyone,” “some,” and “none” are part of the subject. Use the principles that follow to guide you through these special cases.

• Remember that the names of organizations and words such as “everyone,” anyone,” “each”—i.e., words that ask us to consider something one member at a time rather than collectively—are singular.

Each of the student leaders agrees that . . .

Anyone associated with the DEP understands that . . .

• When subjects are connected by the word “or,” the subject closer to the verb determines its number.

Either the pebbles or the sand is . . .

Either the sand or the pebbles are . . .

• When “some,” “all,” or “none” are part of the sentence subject, the number of the verb matches the number of the noun to which “some,” “all,” or “none” refers. Note below how the subject (“sample,” “samples,” etc.) controls the number of the verb.

Some of the sample is contaminated.

Some of the samples are refrigerated.

All of the bone is intact.

All of his bones are broken.

None of the ground is disturbed.

None of the grounds are mowed.

• Although “and” in the subject usually indicates a plural, there are cases where the context is obviously singular, thus requiring a singular noun.

Further research and development on fuel cells is necessary for them to achieve their potential as energy storage devices.

Supply and demand is used to determine the equilibrium values of price and quantity.

• Nouns that are “collective” (automatically suggesting a group) take a plural verb when the group as a whole is meant; they take a singular verb when the group can be thought of as individual members.  Commonly used collective nouns include “number,” “majority,” “series,” and “variety.”  Note that when collective nouns refer to a singular group as a whole they are often preceded by the word “a”; when they suggest individual group members they are often preceded by the word “the.”

A number of people were affected by the tragedy.

The number of samples contaminated was two.

A series of western blots were performed to assay protein expression.

The series of western analyses was found to be inconclusive.

• Units of measure are treated as collective nouns, taking a singular verb.

For each patient, 10 mL of whole blood was collected in a clot tube.

• “Data” can be treated as a singular or plural noun, depending on whether the word refers to a collection of data as one unit or whether individual results are implied.

Once the data is collected, the results can be tabulated.

When data for 2007 and 2008 were compared, the researchers found that violent crime in the city had dropped by 12 percent.