There is no singular, gender-neutral collective pronoun. (from Quora)
1228
Usage of "they" / "them" / "their" when the person's gender is not known
29639
Reason for the current trend to use «she» as the gender-neutral pronoun?
38326
Is "everyone" singular or plural?
32257
Use of "them" as an article, not a pronoun
71868
Subject in sentence with only object pronoun
78514
Why don't English nouns have grammatical gender?
152618
Using "they" in tag questions with everybody/nobody etc
92189
Is there a way to refer to a person (using a pronoun) without mentioning a sex?
121598
Why can't "thanks" ever be singular as a noun?
91524
How to refer to a specific definite person whose gender is unknown
71323
Are there nouns that are always plural — have no plural counterpart?
85071
Specifying Pronouns as He/Him;She/Her;They/Them
131090
On the singular vs plural aspects of "who"
120891
Zero article before the word "part" - what is the particular reason for this?
4852
singular/ plural in the attributive
110155
When are relative pronouns omitted in a sentence?
19231
"None" as plural indefinite pronoun