• 3-minute read
  • 4th April 2019

Word Choice: All vs. All Of

Here, we’re looking at when to use “all of” rather than “all” by itself. Make sure you can avoid errors when using these terms by checking out our guide below.

When to Use “All Of”

The sense of “all” that applies here is its use as a determiner (or a predeterminer). This means using “all” to indicate how much of something we’re discussing. For example, “all students” means “every single student,” not just some of them.

As a rule of thumb, we use “all of” when “all” is a determiner and the next word in the sentence is a pronoun. When this is a personal pronoun (e.g., me, you, us, them) or a relative pronoun (e.g., whom, which), we need the “of” to make the sentence grammatical. For example:

All of you were late to class.
All you were late to class.
These are my students, all of whom were late.
These are my students, all whom were late.

When “all” precedes another determiner as part of a noun phrase, though, the “of” is typically optional. This includes the definite article (i.e., the):

All of the students overslept.
All the students overslept.

Demonstrative determiners (e.g., this, that, these, those):

All of these students were late.
All these students were late.

And possessive adjectives (e.g., my, his, her, your, our, their). For instance:

The students lost all of their homework.
The students lost all their homework.

Some style guides recommend leaving out “of” when it is optional. This will make a sentence more concise, but it is ultimately up to you.

When to Use “All” By Itself

So when do we need to use “all” by itself? As mentioned, you can do this when the next word is a pronoun or determiner. But there are situations when adding the “of” is not an option. These are:

  • When “all” comes before a noun referring to an entire class of things.
  • When “all” is used before an uncountable noun without a determiner (i.e., a noun with no plural form without a word like “the” or “my” in front).

In the case of an plural noun that refers to an entire class, we would write:

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All cats are lazy.
All of cats are lazy.

Here, we use “all” without “of” because “cats” refers to every possible feline, not a specific group of cats. And we would do the same if “all” came before an uncountable noun:

All water is wet.
All of water is wet.

In both cases, the “of” is not just unnecessary; it is grammatically incorrect.

“All” as a Pronoun

We mentioned above that “all” is always followed by “of” when the next word is a personal or relative pronoun. This only applies when “all” is a determiner.

You will also see “all” used as a pronoun meaning “everyone,” “everything,” or “the only thing.” And when “all” is a pronoun, it can be combined with other pronouns without using “of”:

This letter is for all whom it may concern.
All you need is love.

These sentences are both fine as “all” is used as a pronoun, not a determiner.

Summary: All or All Of?

When deciding whether to write “all” or “all of,” keep the following in mind:

  • Use all of when the next word is a personal or relative pronoun.
  • You can use either all or all of when the next word in the sentence is a noun phrase that begins with a determiner.
  • Use all by itself when the next word in the sentence is a plural noun that refers to an entire class of things or an uncountable noun.
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Comments (35)
Ashraf Al Abbadi
29th November 2020 at 06:50
Is the use of "all' in this sentence correct? : "To their astonishment, the lawyer told them that old Nancy left all her money for her two cats."
    30th November 2020 at 10:07
    Hi there. "Her" is a determiner, so either would be fine.
      10th March 2021 at 09:29
      I can't agree with you. "her" isn't a pronoun. It's a possessive adjective in the example. The adjective is determining the noun. So "all" is used before a determiner, not a pronoun! According to your explanation in thgis article, "All" should be optional in his sentence. Nancy left all her money / Nancy left all of her money.
      10th March 2021 at 09:59
      Good point, Amy. We've updated the post to correct the terminological confusion. Thanks.
    7th April 2023 at 00:35
    This is very useful for both teachers and students
      15th April 2023 at 12:43
      Thank you - I'm glad this was helpful!
6th January 2021 at 15:51
Helpful. How do the rules apply when dealing with a plural noun referring to a segment and not an entire class? Is the 'of' optional then? For example: "Pick up all of the rocks in the garden" vs "Pick up all the rocks in the garden"
    6th January 2021 at 16:19
    Hi, Jamie. This should be covered in the first section of the post (the bit with the "All of the students overslept/All the students overslept" examples). The "of" is optional in such cases, though you may want to include it if you're using formal language otherwise.
8th January 2021 at 09:03
I'm currently very stumped on a sentence. It reads "It was my main source of contact to see all my friends." I really want to say that "all of my friends" feels more correct, but I can't back it up either way, it's just my gut. How would the rules apply?
    8th January 2021 at 10:53
    Hi, Dustin. As we note in the post, the "of" is optional when it precedes a possessive determiner, so either "all of my friends" or "all my friends" would be fine (although "all of my friends" is arguably more formal).
      8th January 2021 at 17:25
      Got it, thanks!
14th January 2021 at 00:25
Hello, I'm struggling with "solution to all your transfer needs" or "solution to all of your transfer needs." As well as "provide you with all of the services" or "provide you with all the services." Thank you so much!!
    14th January 2021 at 10:05
    Hi, Niki. This falls under the guidelines about determiners in the post: i.e., either "all of the" or "all the" would be fine in those examples, but "all of the" is arguably more formal, so the best choice will depend on the tone you're aiming for.
Denise Anderson
15th January 2021 at 14:48
Thank you for this page. A few months ago Microsoft started making grammatical suggestions to my documents in Outlook & Word. It always wants to replace my use of "all of" with "all." This page has shown me that my preference for "all of" is appropriate in professional communication - as in "all of my classes."
    15th January 2021 at 15:02
    Glad to be able to help, Denise. In case it helps further, you can either turn off the grammar check in Microsoft Word (as explained here) or customize it by going to File > Options > Proofing in Word and clicking the "Settings..." button in the spelling and grammar section. This should bring up a new menu with a list of stylistic issues that you can check or uncheck as required. I'm not entirely sure which one would be picking up "all of," but possibly the wordiness option? Maybe worth trying if the suggestions are annoying, though!
    19th January 2023 at 15:32
    lol.. this is the exact reason i am here. Microsoft word kept telling me to use all instead of all of
11th June 2021 at 15:11
Great read! Should I say "I finished all of the graphic rows" or I finished all the graphic rows?"
    11th June 2021 at 16:47
    Hi, Ivan. As set out in the post, the "of" is usually optional when the next word is a determiner, including the definite article "the." As such, either of your examples should be fine.
8th July 2021 at 14:31
Would "all the following" or "all of the following" be correct?
    12th July 2021 at 09:10
    Hi, JR. We discuss this in the post using the example of "all of the students/all the students." In short, either form would be fine.
Dana Biernacki
22nd July 2021 at 21:59
Hi. I can't find any examples anywhere with proper nouns. In all Canada or all of Canada—all of sounds right to my ear. Can someone help me? :-)
    23rd July 2021 at 09:01
    Hi, Dana. I'm not aware of any specific rules regarding "all/all of" and country names (or zero article proper nouns in general), so I'd imagine either is broadly acceptable as long as it is clear in context, but I agree that "all of Canada" sound more natural. In addition, "all-[country name]" is sometimes used to mean "entirely of that country" (e.g., an "all-American hero" or similar), so adding "of" may also be a good way to avoid ambiguity on that point.
Theodros Tesfaye
2nd April 2022 at 19:49
When can I use all by itself?
    4th April 2022 at 09:49
    Hi, Theodros. We explain when to use "all" rather than "all of" in the post here (e.g., in the section titled "When to Use 'All' By Itself"). If you have a more specific question, or you're thinking about a combination of "all" with another word, let us know and we can try to offer some guidance.
      Theodros Tesfaye
      17th April 2022 at 15:27
      Can you use all of before a noun or determiner?
      18th April 2022 at 09:33
      Hi, Theodros. As we show in the post, you can use "all" before many plural and uncountable nouns (e.g., "All dogs go to heaven," "All love is sacred"). And you can use "all" with various determiners, including the definite article (e.g., "All the cats are purring"), demonstrative determiners (e.g., "All those children are dirty"), and possessive determiners (e.g., "All their time has been wasted"). There are many examples of nouns and determiners, though, so if you would like more specific advice on something not covered in the post already, let us know and we can try to answer your question.
23rd May 2022 at 12:03
Would it be accurate to say "Win all this" or "Win all of this" when referring to a collection of items for a competition prize? I think either are ok - am I right?
    24th May 2022 at 09:55
    Hi, Lizzie. Yes, both would be fine, so it's mostly a case of what kind of tone/effect you're aiming to achieve (with "Win all of this" a little more formal than "Win all this," but you could also argue that adding the "of" makes it feel a bit more emphatic, if that is what you're going for).
Theodros Tesfaye
11th June 2022 at 12:31
You can use all of when the next word is a determiner, plural demonstrative adjective, or a possessive pronoun. Example: Put all of your dirty clothes in a basket. You can use all before a noun or subject pronoun or after a preposition. Example: The Declaration of Independence clearly stated that America would be a free and independent nation. All Americans would be given life, liberty, and the pursuit of happiness.
Theodros Tesfaye
10th July 2022 at 22:37
Would you use the word all before or after the preposition?
    11th July 2022 at 08:30
    Hi, Theodros. "All" can be used either before or after a preposition depending on the context: e.g., "All of you are my friends" and "You are my best friend of all" are both grammatical sentences. If you need feedback or help with a particular sentence, you might just want to submit the relevant document for proofreading: https://proofed.com/services/proofreading/
Jim McLandress
18th December 2022 at 23:33
Really going back to basics here... what's a "determiner"? I'm guessing it's not the same as GWB being "the decider".
    22nd December 2022 at 13:09
    Hi, Jim. Thanks for your question! A determiner is a word that gives you more information about the noun it precedes to make the meaning clearer. We have a blog article that tells you more about them here https://proofed.com/writing-tips/determiners-what-they-are-how-to-use-them/ There are various categories including possessives, demonstratives, and articles. There’s a mention of “all” here too!
26th June 2023 at 19:18
This post is really helpful! Thank you for the insight.
    Hannah Orde
    5th July 2023 at 10:01
    Glad it was helpful Emma!

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