Expressions of quantity: one of, none of

Expressions of quantity, such as "one of" and "none of," are used to describe the number or amount of something. These expressions play an important role in English grammar and are used to convey specific information about the quantity or lack thereof. Let's take a detailed look at the grammar rules and usage of these expressions.

1. "One of":

   - The phrase "one of" is used to indicate that something or someone is part of a larger group.

   - It is followed by a plural noun, and it is typically used with the definite article "the" before the noun.

Example: "She is one of the students in the class." (She is part of a larger group of students.)

2. "None of":

   - The phrase "none of" is used to indicate that there is no amount or no one among a group of things or people.

   - It is followed by a plural noun, and it is also typically used with the definite article "the" before the noun.

Example: "None of the books on the shelf are mine." (There are no books among the group on the shelf that belong to me.)

Important points to note:

- Both "one of" and "none of" are followed by plural nouns.

- They are usually used with the definite article "the" before the noun, although there may be exceptions.

- The verb that follows these expressions agrees with the noun that follows them.

For example, if the noun following "one of" or "none of" is singular, the verb will also be singular. 

Example: "One of the cars is red." (The noun "car" is singular, so the verb "is" is also singular.)

Example: "None of the students are studying." (The noun "students" is plural, so the verb "are" is also plural.)

- Both "one of" and "none of" can be used with possessive pronouns to indicate ownership or possession.

Example: "One of my friends invited me to the party." (Ownership is indicated with the possessive pronoun "my.")

Example: "None of their suggestions were useful." (Ownership is indicated with the possessive pronoun "their.")

In summary, "one of" is used to indicate that something or someone is part of a larger group, while "none of" is used to indicate the absence of something or someone within a group. These expressions are followed by plural nouns and are typically used with the definite article "the" before the noun. The verb that follows agrees with the noun in terms of number (singular or plural). They can also be used with possessive pronouns to indicate ownership.