In the English language the predicate agrees with the subject in person and number.
a singular subject requires a predicate in the singular, a plural subject requires a predicate in the plural.
(The night was dark & cold)
In Modern English, with its few inflexions, agreement of the predicate with the subject is restricted to the present tense apart from the verb to be. The verb to be is an exception because it agrees with the subject not only in the present but in the past tense as well.
(I am proud of you)
Rules of agreement of the predicate with the subject:
1. The predicate is used in the plural when there are two or more homogeneous subjects connected by the conjunction and or asyndetically.
(His brother & sister were proud of him)
If two or more homogeneous subjects are expressed by infinitives the predicate is in the singular.
(To live & write the book at the ocean was his dream)
2. When the predicate-verb precedes a number of subjects it is often in the singular, especially if the sentence begins with here or there.
(There is a picture & a mirror on the wall)
If the subjects are of different number the predicate agrees with the subject that stands first.
(There was a girl & the men who surrounded her)
3. When two homogeneous subjects in the singular are connected by the conjunctions not only... but (also), neither... nor, either ... or, or, nor, the predicate is usually in the singular.
(Either I or Kate was happy to see him)
If the subjects are of different person or number, the predicate agrees with the one next to it.
(Neither I nor my sister is to blame.)
4. When two subjects in the singular are connected by the conjunction as well as the predicate is in the singular.
(Mary as well as Kate is a good student)
If the subjects are of different person or number, the predicate agrees with the subject that stands first.
(Mary as well as her classmates is good in math)
5. If a subject expressed by a noun is modified by two or more attributes connected by and, the predicate is in the singular when one person, thing, or idea is meant.
(Quit & beautiful night was ruined by the girl’s scream)
If two or more persons, things, or ideas are meant the predicate is in the plural.
(Rock & Pop music are different)
6. If the subject is expressed by a defining, indefinite, or negative pronoun (each, either, everybody, everyone, everything, somebody, someone, something, nobody, no one, nothing, neither, etc.), the predicate is in the singular.
(Nobody was at the lesson)
7. If the subject is expressed by an interrogative pronoun (who, what) the predicate is usually in the singular.
(What is going on?)
If the question refers to more than one person the predicate may be used in the plural.
(Who were on the boat that night?)
8. If the subject is expressed by a relative pronoun (who, which, that) the predicate agrees with its antecedent.
(Mary, who was a student, tried to get a book from the upper shelf)
9. If the subject is expressed by the emphatic it the predicate is in the singular no matter what follows.
(It was these tables which standed in the hall)
10. If the subject is expressed by a noun in the plural which is the title of a book, or the name of a newspaper or magazine, the predicate is usually in the singular.
(“Sunday mirrors” was published yesterday)
11. If the subject is expressed-by a noun in the plural denoting time, measure, or distance, the predicate is in the singular when the noun represents the amount or mass as a whole.
(Thirty three clean sheets of paper is enough?)
12. If the subject is expressed by a collective noun denoting a group or collection of similar individuals taken as a whole (mankind, humanity, etc,) the predicate-verb is in the singular.
(Previous generation of computers was less powerful)
If the subject is expressed by a noun of multitude, i. e. a collective noun denoting the individuals of the group taken separately (people — люди, infantry, cavalry, gentry, clergy, police, cattle, poultry, jury, etc.) the predicate-verb is as a rule in the plural.
(The cavalry were ready to fight)
With collective nouns (family, committee, crew, army, board, chorus, government, party, team, company, band, etc.) as subject the predicate is either in the singular or in the plural; this depends on what is uppermost in the mind, the idea of oneness or plurality.
(The band was organized last year)
The predicate agrees in number with the subject expressed by a syntactic word-group, consisting of two nouns connected by the conjunction and. Here we find agreement according to the meaning expressed in the word-group.
1. (a) If the word-group consists of two nouns denoting different persons, things, or notions, the predicate-verb is in the plural.
(Andreis and I were alone.)
(b) The predicate-verb is in the singular when the subject is expressed by several nouns which represent one person or thing, or two persons or things forming a close unit often corresponding to one notion.
(A carriage and pair was passing through the lodge gates of Transome court.)
2. If the subject is expressed by a word-group consisting of two nouns connected by the preposition with, or the expression together with, the predicate-verb is in the singular.
(A woman with a child on the third floor is screaming and waving her free hand frantically)
3. If. the subject is expressed by a syntactic word-group the first element of which denotes an indefinite number or amount, such as a number of..., a variety of..., the majority of..., a lot of..., plenty of..., a mass of... etc., the predicate may be in the singular or in the plural. In most cases the form of the predicate depends on the form and meaning of the second element, which from a semantic point of view is the dominant element of the word-group.
(A number of cars were parked on the lot before a two-storey building.)
4. If the subject is expressed by the word-group many a... the predicate is in the singular.
(Many a mistake was made by me-lofty, poetic).
5. If the subject is expressed by a group of words denoting arithmetic calculations (addition, subtraction, division) the predicate is usually singular; multiplication presents an exception as the verb may be in the singular or in the plural.
(Two and two is four.)
