All is singular when used as the subject with a linking verb or when it means the only thing or everything:
All I want for Christmas is my two front teeth; all we found was candy
wrappers and soda cans. All may take a plural verb when the context is
plural, often indicated by a prepositional phrase: All of us are happy
to be here.
Along with, as well as, plus, together with
These phrases used after a singular subject, and often set off by
commas, do not change the singular verb: John, as well as Jane, is here;
unemployment plus poverty breeds anger. But note, a compound subject joined by and in
which the writer chooses to set off the second element with commas
still takes a plural verb: John, and his sister, are officers in the
Anyone, each, either, every, everyone, many a, no one, nothing, someone, something
All these indefinite pronouns require singular verbs: Each has his point of view; everyone is welcome; nothing can be done.
Collectives (family, team, couple, etc.) are plural when the component
members are considered separately and singular when the group is handled
as a unit: a score were present; an army marches on its stomach. The
plural prevails when humans are concerned: The couple are. . . . The
decision between singular and plural is frequently writer’s choice. Once
the number is established, be consistent: My family trusts only people
it knows; my family trust only people they know.
Two subjects connected by and usually require a plural verb:
Experience and education are necessary. However, if the compound subject
is considered as a unit, the verb should be singular: Bacon and eggs is
his favorite breakfast; but bacon and eggs are among his least
favorite foods. Sometimes an author will for emphasis separate the
second element of a compound subject with commas. This is not the same
as using along with and still requires a plural verb: John, and his sister, are officers in the company.
Generally a number, fraction, or quantity of things is considered
singular if considered as a mass (ten gallons is enough) and plural if
considered as separate units (ten dishfuls were slowly doled out). Sums
of money, time, distances, and other similar measurements are often
singular (Only years of dedication earns a climber the right to stand on
such a peak).
May take either a singular verb (when it means not one) or a plural verb (when it means not any), but plural is more common: None were up at 7 a.m.; none of it was taken; none of them were here.
One of . . .
This phrase usually is followed by a plural noun, which requires a
plural verb: He is one of the men who have risen quickly to the top; she
is one of those people who get things done.
In a compound subject joined by or, the verb agrees with the final member: Wine or cocktails are served; soft drinks, cocktails, or wine is served.