Most of, Most of the (Many, Some, Any, or All can also be used in the same way)
Most = adjective
Ex: Most students spend a lot of time doing their
IS THE MOST COMMON USE OF “MOST.”
Most of = pronoun, preposition
+ preposition + pronoun)
Ex: Most of them also have to work.
MUST USE AN OBJECT PRONOUN AFTER THE PREPOSITION.
NO EXCEPTIONS! (Most
of + noun DOES NOT EXIST!)
Ex: Most enjoy studying.
(In this sentence, “most” is also a pronoun. It is understood that I am referring back to the subject
“students” mentioned in a previous sentence.)
Most of the
= pronoun, preposition, article
(pronoun + preposition + article + noun)
Most of the students that I know live with their
IN THIS USAGE, YOU ARE REFERRING TO A NOUN
(“students”) THAT YOU FURTHER DEFINE ("that I know") or that
you've mentioned previously.
to understand the difference between the three, you must understand that
prepositions like “of” must always be followed by either a noun or a
noun phrase (adj + N). You
must also know that the object of a preposition can NEVER be the subject
of a clause. Therefore, in the second and third examples, “most” is
a pronoun (it is the subject of the sentence, taking the place of a noun),
but in the first example it is an adjective because it immediately
precedes a noun. You must
also know that “the” is necessary before the noun (as in the third
example) because, when you use “most,” you are referring to a part of
a specific group (“students that I know”).