An indefinite pronoun refers to a general person, place or thing. The verb that follows such a pronoun used as a subject must agree in number with that indefinite pronoun. Possessive pronouns must also agree with the indefinite pronoun they
follow. The following indefinite pronouns are always singular and refer to only one person, place or thing. They are also followed by singular possessive pronouns.
everyone no one
Everything is in its place.
Neither of the men was in his car.
Each of the members presents his guest.
The indefinite pronouns both, few and several are always plural and must be used with plural verbs and may be followed by plural possessive pronouns.
Both of the men are in their cars.
All, none and some are indefinite pronouns that may be used with either singular or plural verbs.
Everyone must do (his*, their) job the best that (they, he*) can.
A few of your answers (is, are*) not quite right.
Some of the grass (needs*, need) cutting.