Singular or plural: agreeing the verb with its subject

A verb agrees with its subject's grammatical number. Collective nouns, quantities, unfamiliar plurals and intervening modifiers can obscure that number; an explicit subject can resolve the uncertainty.

The subject and its number

A singular subject generally takes a singular verb, and a plural subject takes a plural verb: There was three mice becomes There were three mice, and There was not enough samples available becomes There were not enough samples available. ¹ Latin and Greek scientific terms can make a noun's number difficult to recognise, and borrowed plurals may acquire singular meanings in English. ²

A plural-looking ending does not necessarily mean a plural subject: measles, mumps, kinetics, dynamics, politics and mathematics can have singular meanings. ² Genetics is an important scientific field refers to a discipline, whereas the genetics of the fruit fly are well researched refers to a set of characteristics. ²

Data has both traditional plural-count and singular-mass uses. ^{2, 3} Some usage guidance distinguishes a package of information, taking data is, from individual data points, taking data are; scientific-writing guidance that insists on plural data rejects that distinction. ² One editing approach avoids ambiguity in no data is/are transmitted by writing not any data are transmitted. ^{3, 4}

The National Institutes of Health and the Centers for Disease Control and Prevention each identify a single entity and take a singular verb. ⁵ Pants and trousers take plural verbs, as in my pants were tight. ⁶ High jinks also takes a plural verb, as in there were a lot of high jinks at the party, whereas the dice game craps takes a singular verb: craps is a dice game. ^{7, 8}

A plural variable name remains plural: hospital charges were treated as a continuous variable measured in US dollars takes were because the subject is charges. ^{9, 10} An implied phrase such as the variable of does not justify changing that verb to the singular. ^{9, 10} Similarly, the savings associated with therapy were between $12 and $345 takes a plural verb. ^{11, 12}

Collective nouns and quantities

Collective nouns refer to groups, such as a swarm of insects or a choir of singers; agreement depends on whether the group or its individual members are emphasised. ^{13, 14} The distinction appears in these examples: ¹⁴

• The emergency department staff are trained in the latest resuscitation techniques emphasises individuals.
• The hospital's emergency department staff is the best in the city emphasises the group.

¹⁴

British usage is more likely than American usage to treat a business as plural: Bloomingdale's is having a sale on swimsuits contrasts with Fenwick are having a sale on swimming costumes. ¹⁴

A measured quantity considered as one amount takes a singular verb: 20 kilometers is a long walk. ¹⁵ For a volume, After 5 min, 20 µL was injected is appropriate if the whole volume was injected rather than increments. ^{16, 17, 4} If that meaning is not explicit, one volume (20 µL) was injected makes it clear; the same issue can arise with grams. ^{18, 17, 4}

Usage advice on expressions such as majority is not uniform. ^{19, 20} In 2007, one usage adviser recommended, in general, a plural verb after a total, a number, a lot, a variety, a percentage, a majority or an average, and a singular verb after the corresponding expression with the. ¹⁹ Her examples were: ¹⁹

• A total of 100 patients were enrolled in the trial.
• The majority (95%) [of patients] was considered evaluable for the efficacy analysis.
• The number of leukocytes was used to diagnose a fulminating infection.
• The majority of individuals (about 90%) with this genetic enzyme deficiency shows few or no abnormal signs.
• A variety of mechanisms, alone or in combination, are deemed to be causative in cardiogenic shock.
• A number of observations of the sun were made during the eclipse.

^{21, 19}

In a 2010 answer, the same adviser instead recommended the majority of whom were engaged in surgical research, because majority referred to plural registrants. ^{22, 23, 20}

Indefinite pronouns

None can mean not any or not one. ^{24, 25} Usage guidance prefers the plural for not any and the singular for not one, illustrated by: ²⁴

• None of the institutions in the consortium have solutions to the problem of the uninsured.
• As to the candidates for postdoctoral fellowships, none is from this geographic area.
• None [not any] of the aspects of science are learned without diligence.
• None are so blind as those who will not see.
• None [not one] of the Smith family has been designated an heir.
• Of all the features of her face, none is so striking as her blue-violet eyes.

²⁴

An alternative is to replace none with not one or not any, making the intended number explicit. ²⁵

Each is singular when it precedes coordinated nouns, although the coordination may distract from its number. ^{26, 25} Each rat and mouse was diabetic can therefore be made explicit as each animal (rat, mouse) was diabetic. ^{26, 27, 28} The same approach gives each fraction (erythrocyte, plasma) contains linoleic acid. ²⁵ Every is also singular and emphasises an item as part of a group, as in every mussel was analysed. ²⁵

Coordination and as well as

Two subjects joined by and normally form a plural subject: Cystic fibrosis and celiac disease are common causes of malabsorption. ²⁹ Coordinated nouns intended as one unit can take a singular verb, as in a knife and a fork is; orthodontic diagnosis and treatment is taught can be made more explicit as orthodontic management (diagnosis and treatment) is taught. ^{3, 4}

As well as adds a prepositional phrase rather than creating a plural compound subject, so the verb agrees with the original subject. ²⁹ The constructions are Penicillin, as well as the cephalosporins, is a β-lactam antibiotic and Malabsorption, as well as improper diet, leads to vitamin deficiencies. ²⁹

Explicit subjects and recasting

Ambiguity can lie in the subject itself or be introduced by its modifiers. ³⁰ Lexical changes can make the subject explicitly singular or plural where applying agreement rules still leaves uncertainty. ³

In the subcellular location of the truncated subunits was identified, the subject is singular location, not plural subunits. ^{31, 32, 33} One editing revision merges the modifiers as the truncated-subunit subcellular location was identified to remove the distraction of nearby plural subunits. ^{33, 28} A plural subject is less distracted by a singular intervening object, as in different channel estimates in the APML algorithm correspond to a different time interval. ³³

A sample of 50 patients (age 25–50 yr) with a history of focal epilepsy was/were examined can be recast as patients (age, 25–50 yr; n=50) with a history of focal epilepsy were examined, removing the competition between singular sample and plural patients. ³³ Weak quantifiers such as a majority of, a number of, a percentage of, a range of and a variety of can likewise be replaced with an explicit subject, such as most of the proteins were eluted or the proteins (50–60% of the total number) were eluted. ³³

There was/were a monomer and several dimers sets a singular nearby noun against plural coordination. ^{34, 3} Recasting as there was a combination (monomer, several dimers) present makes the subject singular; there were three RNAs: tRNA, mRNA, and rRNA instead puts a plural summary before a list. ^{35, 4, 3}

A ratio with an apposed percentage can also be recast: One in 77 New Yorkers—1.3% of the population—have been diagnosed with HIV/AIDS becomes HIV/AIDS has been diagnosed in 1 of 77 (1.3%) of New Yorkers. ^{36, 37}