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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
that which
Grammar usage guide and real-world examplesUSAGE SUMMARY
"that which" is correct and can be used in written English.
You can use it when introducing a clause that provides further information about a subject. For example: "He is a man of honor, that which I admire most about him."
✓ Grammatically correct
News & Media
Science
Academia
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
"Worse than that which existed in South Africa".
News & Media
Tattvartha Sutra: That Which Is.
Academia
To that which was first charged, or to that which was first committed?
Academia
She [Sarah] blasted that, which was good.
News & Media
"It's things like that which undermine Michelin".
News & Media
That Which Does Not Kill You.
Science & Research
That which was special becomes that which is routine.
News & Media
That which is common unites.
Notice that, which implies (2.29).
Science
That which is scheduled gets done.
News & Media
It follows that, which further implies that.
Expert writing Tips
Best practice
Vary your sentence structure by occasionally using "that which" instead of simpler alternatives like "what" or "that" to enhance readability and stylistic flair.
Common error
Avoid using "that which" excessively in casual conversation or informal writing. Overusing this phrase can make your language sound stilted or pretentious. Simpler alternatives are often more appropriate.
Source & Trust
81%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "that which" functions as a relative pronoun, introducing a relative clause that modifies a noun or pronoun in the main clause. Ludwig AI indicates this construction is grammatically correct and widely used.
Frequent in
News & Media
37%
Science
35%
Academia
20%
Less common in
Encyclopedias
5%
Formal & Business
3%
Reference
0%
Ludwig's WRAP-UP
In summary, "that which" is a grammatically correct and frequently used phrase that functions as a relative pronoun, introducing a clause to provide further information about a preceding noun. Ludwig AI confirms its validity and widespread usage. While it can add a formal tone to writing, overuse in informal contexts should be avoided. Alternatives like "what" or "that" may be more appropriate in casual settings. Common in News & Media, Science, and Academia, "that which" can be a valuable tool for precise and nuanced communication.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
what
Uses a single word to replace the entire phrase, simplifying the sentence structure.
that
A more concise way to refer to something previously mentioned or understood.
the thing that
More explicit and less formal than "that which".
the one that
Emphasizes a specific item or individual among others.
what is
Highlights the state or condition of something.
that what
Less common and slightly redundant, but still conveys the same meaning.
anything that
Broadens the scope to include any item or action fitting the description.
everything that
Encompasses all items or actions fitting the description.
the item which
More formal and specific, often used in technical or legal contexts.
the aspect that
Focuses on a particular feature or characteristic.
FAQs
How can I use "that which" in a sentence?
Use "that which" to introduce a clause that provides further information or clarification about something previously mentioned. For instance, "He valued integrity, "that which" guided his decisions."
What phrases are similar to "that which"?
Similar phrases include "what", "that", and "the thing that". The choice depends on the desired level of formality and clarity.
Is it always appropriate to use "that which" in writing?
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Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
81%
Authority and reliability
4.5/5
Expert rating
Real-world application tested