All parts of a sentence should agree. Generally, if the subject is singular, the verb should be singular, and if a pronoun refers back to that singular subject, it should be singular in form, too. We use the word antecedent to describe the noun that the pronoun represents. Similarly, if the subject is plural, the verb should be plural, and any pronoun referring back to the antecedent should be plural.
Hongzia + drives + her car to school.
(singular feminine subject & antecedent) + (singular verb) + (singular feminine pronoun)
Silvio and Anastasiia + drive + their cars to school.
(plural masculine & feminine subject & antecedent) + (plural verb) + (plural nonbinary pronoun)
Durand + drives + their cars to school.
(singular nonbinary subject & antecedent) (singular verb) (singular nonbinary pronoun)
Remember that nouns and their respective pronouns must agree in person (I/me, you, they/she/he), number (singular or plural), and gender (nonbinary, feminine, masculine, or nonhuman: they, she, he, it).
The following words are considered singular and take a singular verb and pronoun:
One of my friends serves as a representative for her dormitory floor.
Either of the boys makes a good choice because of his dependability.
Each of the students has responsibility for their own work.
Everyone at work is expected to take their lunch when scheduled.
Nobody wants to take on cleaning the basement as their spring project.
You may struggle with pronoun choice in sentences using words like anyone, everyone, each, etc. If these words are singular in meaning and the pronoun referring back to them has to be singular, using the feminine her or the masculine him may insult some people.
The following collective or group words take a singular verb and singular pronoun if you are thinking of the group as a unit or whole but take a plural verb and plural pronoun if you are thinking of the individuals in the group:
audience, band, choir, class,
committee, corporation, crowd,
dozen, family, flock, group, heap,
herd, jury, lot, number, public, team
Note the use of subject, verb, and pronoun agreement in the following special sentence constructions: