Subject-Verb Agreement :
Basic Principle: Singular subjects need singular verbs; plural subjects need plural verbs. My brother is a nutritionist. My sisters are mathematicians.
The indefinite pronouns anyone, everyone, someone, no one, nobody are always singular and, therefore, require singular verbs.
Some indefinite pronouns such as all, some are singular or plural depending on what they're referring to. (Is the thing referred to countable or not?) Be careful choosing a verb to accompany such pronouns.
On the other hand, there is one indefinite pronoun, none, that can be either singular or plural; it often doesn't matter whether you use a singular or a plural verb unless something else in the sentence determines its number. (Writers generally think of none as meaning not any and will choose a plural verb, as in "None of the engines are working," but when something else makes us regard none as meaning not one, we want a singular verb, as in "None of the food is fresh.")
Some indefinite pronouns are particularly troublesome Everyone and everybody (listed above, also) certainly feel like more than one person and, therefore, students are sometimes tempted to use a plural verb with them. They are always singular, though. Each is often followed by a prepositional phrase ending in a plural word (Each of the cars), thus confusing the verb choice. Each, too, is always singular and requires a singular verb.
You would always say, "Everybody is here." This means that the word is singular and nothing will change that.
Don't let the word "students" confuse you; the subject is each and each is always singular Each is responsible.
Phrases such as together with, as well as, and along with are not the same as and. The phrase introduced by as well as or along with will modify the earlier word (mayor in this case), but it does not compound the subjects (as the word and would do).
The pronouns neither and either are singular and require singular verbs even though they seem to be referring, in a sense, to two things.
In informal writing, neither and either sometimes take a plural verb when these pronouns are followed by a prepositional phrase beginning with of. This is particularly true of interrogative constructions: "Have either of you two clowns read the assignment?" "Are either of you taking this seriously?" Burchfield calls this "a clash between notional and actual agreement."*
The conjunction or does not conjoin (as and does): when nor or or is used the subject closer to the verb determines the number of the verb. Whether the subject comes before or after the verb doesn't matter; the proximity determines the number.
Because a sentence like "Neither my brothers nor my father is going to sell the house" sounds peculiar, it is probably a good idea to put the plural subject closer to the verb whenever that is possible.
The words there and here are never subjects.
With these constructions (called expletive constructions), the subject follows the verb but still determines the number of the verb.
Verbs in the present tense for third-person, singular subjects (he, she, it and anything those words can stand for) have s-endings. Other verbs do not add s-endings.
Sometimes modifiers will get betwen a subject and its verb, but these modifiers must not confuse the agreement between the subject and its verb.
Sometimes nouns take weird forms and can fool us into thinking they're plural when they're really singular and vice-versa. Consult the section on the Plural Forms of Nouns and the section on Collective Nouns for additional help. Words such as glasses, pants, pliers, and scissors are regarded as plural (and require plural verbs) unless they're preceded the phrase pair of (in which case the word pair becomes the subject).
Some words end in -s and appear to be plural but are really singular and require singular verbs.
On the other hand, some words ending in -s refer to a single thing but are nonetheless plural and require a plural verb.
The names of sports teams that do not end in "s" will take a plural verb: the Miami Heat have been looking , The Connecticut Sun are hoping that new talent . See the section on plurals for help with this problem.
Fractional expressions such as half of, a part of, a percentage of, a majority of are sometimes singular and sometimes plural, depending on the meaning. (The same is true, of course, when all, any, more, most and some act as subjects.) Sums and products of mathematical processes are expressed as singular and require singular verbs. The expression "more than one" (oddly enough) takes a singular verb: "More than one student has tried this."
If your sentence compounds a positive and a negative subject and one is plural, the other singular, the verb should agree with the positive subject.