Here's a breakdown:
Always Singular:
* All: Refers to the whole of a group or thing. Example: "All of the water is gone."
* Any: Refers to one or more of an unspecified number. Example: "Are there any questions?"
* Each: Refers to every single one of a group. Example: "Each student had a turn."
* Every: Similar to "each," referring to all members of a group. Example: "Every member voted."
* None: Refers to not one or any. Example: "None of the students were late."
* One: Refers to a single person or thing. Example: "One person volunteered."
Singular or Plural:
* Some: Can be singular or plural depending on the noun it refers to.
* Singular: "Some information was missing."
* Plural: "Some people are waiting."
* Most: Can be singular or plural depending on the noun it refers to.
* Singular: "Most of the work is done."
* Plural: "Most of the workers left early."
Key Takeaways:
* Context matters: The singular or plural form of "some" and "most" depends on the noun they refer to.
* Agreement: The verb used with these indefinite pronouns should agree with the noun in number.
* Be careful with "none": While often treated as singular, "none" can sometimes be used as a plural when referring to countable things. Example: "None of the books were available."
Remember, it's always best to check the context to determine the correct form of the indefinite pronoun.