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Knowledge on or Knowledge of: Which Is Correct?

Choosing the right preposition to follow a noun can be tricky for English as a second language. Even native speakers often find it hard to know and explain why they choose a particular preposition which “sounds” better than another. For instance, is it “knowledge on” or “knowledge of”?

“Knowledge of” is the preferred prepositional phrase to use in standard US English. “Knowledge on” may be used occasionally, even in reputable sources, but it is not standard English. However, “knowledge about” is an acceptable alternative usage and, in some senses, might be preferable to “knowledge of.”

This article will examine prepositions, how we pair them with the noun “knowledge,” and how English comes to choose and use these words when paired with nouns or pronouns to form a prepositional phrase. 

We will also discuss the nature of countable and uncountable nouns and look at other expressions in which the word “knowledge” adopts a different meaning.

Gaining a Working Knowledge of Prepositions

A preposition is a word or a group of words that show the relationship between its object — a noun or pronoun that follows the preposition — and another word in the sentence.

Prepositions and Relationship

This relationship usually tells us something about time, location or place, movement or direction, or other associations such as manner, measure, source, possession, and instrumentality.

Time: tells us when something happens, in the past, present, or future. Examples of this type of preposition are before, during, after, and since.

Location or place: the location or place where something happened: above, below, under, between.

Movement or direction: towards, across, up, down, and around.

Manner: describes the way things happen or the means by which they occur.

  •  He went on foot to the station, then traveled by train to the city.

Measure: indicates the quantity of something.

  • I measured out the curtain fabric by the yard.
  • I bought half a pound of almonds at the store.

Source: indicates where something or someone originated.

  • The song was sung by the choir.
  • Joe received an email from his uncle.

Possession: indicates the ownership of something by someone or something else.

  • He is a friend of mine.
  • The girl with the sunglasses smiled at me.
  • This book belongs to you, doesn’t it?

Agency or Instrumentality: indicates an action performed on something or someone by something or someone.

  • The house was designed by an architect.
  • He cut the steak with a sharp knife.


Note that prepositions may appear before the noun or pronoun or after the noun or pronoun.

  • Before: in a month, under the tree, by mistake, on purpose.
  • After: different from, disagree with, request for, interested in.

Language experts sometimes distinguish between these two placements by calling the first (i.e., preposition before the noun) a preposition and the second (preposition after the noun) a postposition — together called “adpositions” (source).

But for simplicity’s sake, and for our purposes here, we will refer to both structures as prepositions.

The Simple Prepositions “of” and “on”

Image by Arek Socha via Pixabay

Still, what is the function of the prepositions “of’ and “on” in the expressions “knowledge on” and “knowledge of”? They’re certainly not prepositions of time, place, movement, or measure. 

It may be tempting to describe “knowledge on” as a preposition of manner, as in the way one acquires knowledge, but this is not standard usage. It’s even more tempting to consider “knowledge of” as one of possession — we all possess some knowledge, don’t we?.

When we use “from” or “by” instead, they could be prepositions of source, as in “Where does this knowledge originate?” None of these quite seem to appropriate for our usage of “of” and “on” here.

“At,” “in,” “of,” and “on” are examples of simple prepositions in contrast to compound prepositions or phrasal prepositions. In English, we often use “of” and “on” to introduce the object of verbs (source). However, we also use them to introduce the object of a preposition within a prepositional phrase (source).

In this article, we will look at the placement of the preposition “on” or “of” after the noun “knowledge.” 

Knowledge of

In this case, “knowledge” is the direct object of the verb, and the preposition “of” introduces the object of the preposition.

  • He possesses a knowledge of masonry.
  • My teacher demonstrated a solid knowledge of the subject.

In these examples, we use “of” to combine two nouns so that the second one provides more information about the first noun (source). Here, we use “of” in the sense of being part of something or relating to something, “knowledge,” so we can view it as a preposition of possession (source).

Knowledge on

We most often apply “on” to something on a surface or object, but we can sometimes apply it to ideas, books, or discussions on a particular subject that are concerned with that subject. However, we see this far less often with “knowledge,” and many spell-checkers will flag this as incorrect.

  • The professor displayed his knowledge on genetics.

We might see “knowledge on” when an author describes the effect of knowledge on something else (source).

  • The professor described the effect of knowledge on society.

Here, we have a prepositional phrase within a prepositional phrase.

We will examine the standard usage and compare this with “knowledge on” and “knowledge about” in the following sections.

For a related topic, make sure you check out our article, “In the Beginning or At the Beginning: Understanding When to Use Each Phrase,” where we discuss the correct use of the prepositions “in” and “at.”

“Knowledge of” Is Standard English Usage

No one ever claimed that English was an easy language to master! However, a combination of the strategies above will usually provide answers to questions of standard English usage.

We ought to remember, though, that standard English, like all other languages, develops over time as speakers use and adapt it to their purpose. 

This flexibility doesn’t mean that we can make it up as we go along — we would hardly understand each other were that the case! But there is sometimes some flexibility in which prepositions we may choose to use.

We frequently point you to a solid dictionary when looking for answers to correct English usage. In this case, it is worth noting that the Merriam-Webster dictionary uses “knowledge of” in all its examples and not “knowledge on” (source).

Is “Knowledge on” or “Knowledge about” Correct?

So, if we accept — as we should — that “knowledge of” is the commonly accepted phrasing, are there instances when “knowledge on” is acceptable or even preferable? And are there any other possible prepositional phrases to pair with “knowledge”?

Understanding When to Use Each

Some sources suggest that we better apply “knowledge of” to something that a person is personally familiar with (subjective knowledge). In contrast, we can use “knowledge on” and “knowledge about” more suitably to subject knowledge of a field of study (objective knowledge).

However, there is little evidence to suggest that this fine distinction between subjective and objective knowledge has as much merit or support from the language community, whereas “Knowledge of” and “Knowledge about” have far more support.

Knowledge on

Still, we will find “knowledge on,” even in academic sources. Take the following sentence as an example:

The student demonstrated a thorough knowledge on the subject of Abraham Lincoln.

The suggestion here is that the student did not have any kind of personal acquaintance with Abraham Lincoln (knowledge of Abraham Lincoln) but, rather, she had an understanding of the subject matter (knowledge on the subject of Abe Lincoln).

There is some evidence, then, to support the use of “knowledge on” when applied to a field of study. We’ve taken these sentence extracts from an academic journal article (source):

…the current state of knowledge on aetiology, diagnosis, management, and therapy of myocarditis…

…in relation to knowledge on soil fertility… 

Note the use of “of” here would sound repetitive.

Knowledge about

One will find some usage of the term “knowledge about” in recent times, as in these sentences taken from an article entitled “Knowledge in the Classroom” (source):

When children have limited knowledge about the world, they have a smaller capacity to learn more about it.

You don’t need detailed knowledge about Benedict Arnold’s life to understand what is meant by the relationship between Benedict Arnold and a traitor.

In both of these sentences, we could just as well have substituted “knowledge of” for “knowledge about.” “Of,” “on,’ and “about” are largely synonyms when we use them in the sense of “concerning” or “related to.”

Also, because the primary meaning of the word “about” is “on the subject of” or “relating to,” some may argue that “about” is a better preposition than “of” to use here. 

In this case, we have a greater degree of personal choice, whereas using “knowledge on” is more likely to raise eyebrows.

How English Chooses Prepositions

There are no hard-and-fast rules when it comes to linking many individual prepositions with their noun phrases. As a consequence of the lack of guidelines, some studies have shown that preposition errors represent the biggest category of common grammatical errors amongst non-native speakers (source).

Fortunately, there are some tried-and-tested strategies for avoiding these errors. The first strategy, and this applies to so much regarding learning to speak and write fluently in English, is to read English works as much as possible to familiarize yourself with the correct usage.


Secondly, always proofread your writing and cross-check with a good dictionary to ensure the correct usage. For example, if you should look up the word “knowledge” in the Oxford New Essential Dictionary, you will find that this noun is usually, but not always, followed by the preposition of.

This and Dreyer’s Style Guide are helpful resources for second-language students.

A collocation dictionary is also a useful source listing common word combinations that are the building blocks of natural-sounding English. One popular collocation dictionary lists only “of” as a preposition to follow the word “knowledge” (source).

Netspeak is yet another tool to check for common phrase usage, and you can also use Google Ngram Viewer that charts the frequency of use of any set of words or phrases (source).

For example, if we search for the frequency of usage between “knowledge of” and “knowledge on” in the Ngram Viewer, we find that “knowledge of” is the overwhelmingly more common usage. In contrast, English speakers hardly ever use “knowledge on” (source).

Finally, a third strategy for learning how to choose the correct preposition is to memorize available lists of commonly paired prepositional phrases, as you would do for learning English idioms, for example. You’ve really just got to learn which prepositions go with which words (source)

Countable and Uncountable Nouns

While we’re increasing our knowledge of choosing which preposition goes with which noun phrase, let’s touch on the tricky subject of nouns and their number. Here, the word “number” refers to singular (one) and plural (more than one).

Most nouns perform the function of naming things. A tree and a bird are the names of two things I see when I look out o my window, and I can usually count these. I can see many different trees and a whole flock of birds in my garden.

Knowledge Is an Uncountable Noun

But there are some things that we cannot count, which we call uncountable nouns because they represent ideas rather than things. “Knowledge” is one such uncountable noun. We cannot have two different “knowledges” or separate “knowledges” into cartons as we could do for apples or Lego blocks.

There are many examples of uncountable nouns. The abstract concepts of happiness, art, music, and love; foodstuffs (milk, bread, butter, sugar, water), utilities (gas, electricity), advice, news, information, research, luggage, furniture, money, and so on, are all uncountable nouns, and we never use them in the plural. 

Although none of these uncountable nouns take a plural form, we can talk, for example, about the visual arts when referring to painting and sculpture and the performing arts when referring to music and drama. But we still need to learn which nouns are countable and which are not.

Other Expressions Using the Word “Knowledge”

Although we have seen that “knowledge” is an uncountable noun, we can still use the word with an article (a, an, the) before it, as in:

He has a thorough knowledge of good grammar.

The knowledge of his success boosted his confidence.

“Knowledge” also forms the basis of many common English phrases (source):

Common knowledgeFamiliar to most people
To (the best of) my knowledgeJudging from my personal experience and information
Safe in the knowledge thatKnowing that
It has come/been brought about to our knowledgeWe have discovered
To deny all knowledge ofTo claim ignorance of something — usually to avoid accusations of wrongdoing
A working knowledge of A basic understanding and application of skill
Explicit knowledgeKnowledge that someone can express and store in words, numbers, symbols, etc.
Implicit/Tacit knowledgeKnowledge  acquired from personal experience that cannot be taught or learned from books
Product knowledgeTechnical information about the products manufactured and marketed by an organization

Final Thoughts

In English, “knowledge of” is the preferred prepositional phrase, although we can occasionally see “knowledge on” and “knowledge about.” If one is unsure of the correct preposition to follow (or precede) a noun, a good dictionary will usually provide the answer.

Textbooks and online resources of grammar and English usage will often include tables of such pairings. As a last resort, it is always an option to learn these correct pairings off by heart. 

A far more pleasant way to learn, however, is to read as much and whenever possible. In this way, you will soon begin to absorb the sounds and rhythms of the language.