Is “of ” necessary in “all of ”?

Question

Listen to all your fans

vs

Listen to all of your fans

OR

Name all the states

vs

Name all of the states

What part of language is of in these examples? Is it necessary or optional, correct or incorrect?

When a pronoun follows "all", I think all us would agree that the "of" is needed.
@PeterShor Be careful with that. A lot of people can’t tell the difference between a personal pronoun and a personal adjective, and you don’t need an of in phrases like “all my children”, which uses a personal adjective.

YatharthROCK · Answer 1 · 2012-09-11 14:08:26Z

Of is just a preposition used to say what group or whole includes the part denoted by the preceding word:

Example: most of/ one of/ several of my friends etc.

In the case of all, half, and both; of is optional and you can either omit it or keep it.

But you can't leave out of before the pronouns us, you, them, and it *.

^{*You don't need to worry about this with "both" because you're not going to say "both of it" anyway.}

Nick · Answer 2 · 2012-09-11 14:35:53Z

Of can generally be omitted in most cases or reworded to avoid.

For "all of", you could easily replace it with "every" or "each"

In the two examples you gave, the expression could be eliminated entirely with no loss of meaning.

Listen to your fans.

Name the states.

are both clear without adding "all of" or "all"

Whenever I am writing, and I see the word "of" I stop to consider if it can be worded better.

2 Answers