I am a newbie to GMAT preparation and planning to take GMAT in the next couple of months or so.
Below are the few points on the Subject-Verb agreement that might be useful .
(1) When subjects are connected by or/nor, the subject closer to verb determines the number of the verb
(2) Some of the votes seem to have been miscounted
Here some is the subject. But votes make it countable. So we need plural verb
(3) Everyone seems to be a plural word, but it is always singular
(4) The subject is not compounded by phrases such as along with, together with, and as well as
(5) The subject comes after the verb in constructions that begin with here or there
(6) Three-quarters of the students represents a countable number.
(7) Three-quarters of the student body represents a lump sum, a singular entity.
(8) A high percentage of the population: is singular
(9) A high percentage of the people: is plural
Rule: With words that indicate portions – percent, fraction, part, majority, some, all, none, remainder, and so forth – look at the noun in your of phrase (Object of the preposition) to determine whether to use a singular or plural verb. If the object of the preposition is singular, use a singular verb. If the object of the preposition is a plural verb, use a plural verb.
Example: Fifty percent of the pie has disappeared
A high percentage of the population is …, A high percentage of the people are …
(10) None is singular or plural? – Not sure, better think of it as Plural.
(11) When either/ neither are subjects, they always take singular verb
(12) Use singular verb with sums of money or periods of time
Ex: Ten dollars is a high price to pay, Five years is the maximum sentence for that offense.
(13) Sometimes the pronoun who, that, or which is the subject of a verb in the middle of the sentence. The pronouns who, that, and which become singular or plural according to the noun directly in front of them. So, if that noun is singular, use a singular verb. If it is plural, use a plural verb.
Examples: Salma is the scientist who writes/write the reports.
The word in front of who is scientist, which is singular. Therefore, use the singular verb writes.
He is one of the men who does/do the work.
The word in front of who is men, which is plural. Therefore, use the plural verb do.
(14) Collective nouns: depends on the usage. Ex: team, staff
Usage: The staff is in meeting, The staff are in disagreement about the findings.
(15) Indefinite pronouns: All/ Some. Singular/Plural depends on what they are referring to. i.e, is the thing referring to countable or not.
(16) Indefinite pronouns: Everyone, Everybody, Each require singular verb.
(17) Words joined to a singular subject by with, as well as, along with are parenthetical. The verb should be put in the singular.
(18) The words there and here are never subjects.
(19) Either, neither, each, everyone, many a must be followed by a singular verb
(20) Two nouns qualified by each or every, even though connected by and, require a singular verb.
(21) Looks plural but singular – News, politics, wages, mathematics
(22) Looks singular but plural – dozen cost
(23) Singular verbs needed for – The Arabian Nights, The United States
(24) If the nouns suggest one idea to the mind, or refer to the same person or thing, the verb is singular
Example: bread and butter is; time and tide waits for no man; the novelist and poet is dead
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Please feel free to add/correct if anything needed.