The answer to both of your questions is undoubtedly yes, but I think it will be more instructive if those words that you enumerated are formally identified and classified according to usage.
Those words are indefinite pronouns—pronouns that refer to an unspecified person, thing, or amount, such as “anybody” or “anyone” for no matter what person, “anything” for no matter what thing, and “enough” for as much or as many as needed. They are distinct from definite pronouns, which replace nouns whose identity has been clearly given, such as the personal nouns “I,” “you,” and “she” for specifically named or identified persons; and the demonstrative pronouns “this” and “that” for a person, thing, or idea that’s present or near or that has just been mentioned.
By function, indefinite pronouns are classified into quantifiers or modifiers that limit number or quantity, such as “some,” “any,” or “several”; universals or modifiers that refer to an entire group or concept, such as “all,” “every,” and “each”; and partitives or modifiers that indicate a non-specific quantity, such as “either,” “neither,” and “anyone.” Many of the indefinite pronouns can also serve as determiners, which are words or group of words that introduce a noun to denote an indefinite quantity or a definite but unknown people and objects, such as “several” in “several ships” and “a lot of” in “a lot of participants.”
Having already mapped the domain of indefinite pronouns, we can now take up the matter of which of them are always singular and which are always plural.
The indisputably singular indefinite pronouns are these: “another,” “anybody”/“anyone,” “anything,” “each,” “either,” “enough,” “everybody”/“everyone,” “everything,” “less,” “little,” “much,” “neither,” “nobody”/“no one”, “nothing,” “one,” “other,” “somebody”/“someone,” and “something.” They always take the singular form of verbs, as in “You’ve made so many mistakes today and another is unacceptable” and “Nothing scares me more than meeting a drug-crazed gunman in the street.”
On the other hand, the indisputably plural indefinite pronouns are the following: “both,” “few,” “fewer,” “many,” “others,” “several,” and “they.” They always take the plural form of verbs, as in “You can assign me to Manila or Jakarta; both are acceptable to me” and “Fifty applicants applied for the job and several have been shortlisted.”
There are indefinite pronouns, though, that can be singular or plural depending on context. They are “all,” “any,” “more,” “most,” “some,” and “such.” For instance, “all” is singular in sense in the sentence “All is fair in love and war” but plural in sense in “We expect exactly 120 participants in this convention; all have arrived.” In the same token, “more” is notionally singular in “This is all the money I have right now but there is more in our joint savings account” but notional plural in “Only six trainees are with us now but more are joining us this next week.”
Still debated today is whether the indefinite pronoun “none” should always be treated as singular. Since “none” means “no one” and “one” is obviously singular, some argue that it should always take a singular verb in the context of countable nouns, as in “We interviewed nine applicants but none has met our expectations.” Grammatically, however, there’s nothing wrong in using “none” in the plural as well depending on context and emphasis, as in “We interviewed nine applicants but none have met our expectations.”
