10.2.1. Singular or plural agreement?
There are specific rules for collective nouns, sums of money, percentages or fractions, countries and organisations with plural names, etc.
Collective nouns take the singular when the emphasis is on the whole entity:
The government is considering the matter.
The Commission was not informed.
Use the plural when the emphasis is on individual members:
The police have failed to trace the goods.
A majority of the committee were in favour.
Sums of money can take a singular or plural verb:
EUR 2 million were/was made available.
Percentages and fractions of countable nouns take a plural verb:
Three quarters of the flowers were used.
75 % of the flowers were used.
but uncountable nouns take a singular verb:
Three quarters of the flour was used.
75 % of the flour was used.
Countries and organisations with a plural name take the singular:
The Netherlands is reconsidering its position.
The United Nations was unable to reach agreement.
Words ending in -ics are singular when used to denote a scientific discipline or body of knowledge (mathematics, statistics, economics) but plural in all other contexts.
Economics is commonly regarded as a soft science.
The economics of the new process were studied in depth.
Data can be used as a plural or a singular noun.
Multiple subject. Use a singular verb when a multiple subject clearly forms a whole:
Checking and stamping the forms is the job of the customs authorities.