Determiners are “quantifiers”. They are used before nouns to say how much or how many of something we are talking about. They are sometimes followed by of (usually to talk about a particular group). They are sometimes used without of (usually to talk about a general group).

When all, most, some, and a few are used to talk about people or things in general, they are used without of.

General Statements (determiner + noun) All elementary schools have math teachers.

No student in my class likes exams.

Most students like stories.

All, most, some, and a few are used with of when they refer to more specific people or things; before other determiners such as the, my, your, this, that; or before object pronouns such as us or them.

Most of my friends go to the library after school. Specific Statements (determiner + of + determiner + noun)

All of the students enjoyed the science class.

Most of those students in C ameroon speak both English and French.

Specific statements with object pronoun (determiner + of + object pronoun) All of them liked the camping trip.

A few of us didn’t close both eyes.

Most of us contributed to the picnic.

The exceptions are a lot of, which is a fixed expression, and all. With all, of is optional before determiners, but not before object pronouns.

A lot of the students go to school by bus. A lot of students go to school by bus. A lot of them go to school by bus.

All my friends have lunch together. All of my friends have lunch together. All of us have lunch together.

No is not followed by of or by a determiner.

No students disrespect the teacher.

After none of + plural noun or pronoun, the verb can be plural or singular, though some people think a singular verb is “more correct.”

None of the students was / were uninterested.