Used and loved by millions
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com
they know of
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "they know of" is correct and usable in written English.
It can be used when referring to someone's awareness or knowledge about a particular subject or situation. Example: "They know of the challenges we are facing in the project and are willing to help."
✓ Grammatically correct
News & Media
Science
Wiki
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Human-verified examples from authoritative sources
Exact Expressions
60 human-written examples
What do they know of their targets?
News & Media
What do they know of yours?
News & Media
Maybe they know of some solutions!
News & Media
Investigators say they know of no suspects.
News & Media
They know of what they speak.
News & Media
WHAT do they know of money, who only money know?
News & Media
Or did they know of actual threats against us?
News & Media
The first victim they know of was prostitute Roxene Roggasch.
News & Media
What do they know of football that only football know?
News & Media
What do they know of economics who only economics know?
News & Media
So I think they know of international football.
News & Media
Expert writing Tips
Best practice
Use the phrase "they know of" when indicating that a group has some awareness or information about a topic, but not necessarily a deep understanding. For example, "They know of the risks involved in the project."
Common error
Avoid using "they know of" when you mean they have direct, comprehensive knowledge. Instead, use "they know" to indicate complete understanding.
Source & Trust
80%
Authority and reliability
4.1/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "they know of" functions as a verbal phrase indicating that a group possesses some level of awareness or information about something. Ludwig AI validates the correctness and usability of this phrase, demonstrated through numerous examples.
Frequent in
News & Media
37%
Wiki
27%
Science
23%
Less common in
Formal & Business
8%
Encyclopedias
0%
Reference
0%
Ludwig's WRAP-UP
In summary, "they know of" is a versatile phrase used to indicate that a group has some awareness or information regarding a particular subject. Ludwig AI confirms its grammatical correctness and common usage across diverse contexts, including news, science, and general writing. The phrase serves to establish a level of familiarity or acknowledgment without implying deep or comprehensive knowledge. While appropriate for both formal and informal settings, it's important to differentiate its meaning from "they know", which suggests a more thorough understanding. As Ludwig demonstrates, understanding subtle distinctions in phrasing allows for more precise and effective communication.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
they are aware of
Replaces "know of" with a more formal synonym, emphasizing consciousness of something.
they are familiar with
Suggests a degree of acquaintance or experience with the subject matter.
they have knowledge about
Emphasizes the possession of information, being more specific than simply 'knowing'.
they are informed about
Implies that they have received information, focusing on the source of their knowledge.
they have heard about
Indicates that the information was received by hearing it rather than experiencing it directly.
they are cognizant of
A more formal and emphatic way of saying they are aware of something.
they understand
A simpler phrase that may work in some contexts, although it implies deeper knowledge than "know of".
they have been told about
Highlights the act of someone informing them, shifting the focus to the communication.
they are acquainted with
Implies a personal or direct familiarity, often suggesting a social connection.
they recognize
Suggests acknowledgment and identification of something, rather than detailed knowledge.
FAQs
How can I use "they know of" in a sentence?
You can use "they know of" to indicate that a group is aware of something, even if their knowledge is not complete or detailed. For example, "They know of the issues but aren't fully informed."
What's the difference between "they know of" and "they know"?
"They know of" implies awareness or recognition, while "they know" indicates deeper understanding or familiarity. If you need to say that someone has received information rather than experienced it directly, use "they have heard about".
What can I say instead of "they know of"?
Alternatives include "they are aware of", "they are familiar with", or "they have knowledge about depending on the context".
Is "they know of" formal or informal?
"They know of" is generally considered neutral in tone and can be used in both formal and informal contexts. Alternatives like "they are cognizant of" can be employed for heightened formality.
Editing plus AI, all in one place.
Stop switching between tools. Your AI writing partner for everything—polishing proposals, crafting emails, finding the right tone.
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
80%
Authority and reliability
4.1/5
Expert rating
Real-world application tested