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
which are used
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "which are used" is a perfectly acceptable phrase to use in written English.
It is typically used to introduce additional information about a particular subject. For example: "Roses are one of the most popular flowers, which are used most often in bouquets for special occasions."
✓ Grammatically correct
Science
News & Media
Encyclopedias
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
Let us introduce the following hypotheses which are used hereafter.
Which are used by leading automobile company.
Science
pinnatifida, which are used in traditional medicines for various purposes.
Instead, users pay for credits, which are used to send messages and open chat sessions.
News & Media
It is gradually phasing out the DC-9's, which are used on short-distance flights.
News & Media
The decision affected Waters's Quattro Ultima mass spectrometers, which are used to analyze chemicals.
News & Media
Aerospace has developed some interesting telecom chip technologies, which are used for broadband.
News & Media
Britain also has a number of outdoor tracks which are used in the summer.
News & Media
CNA Surety sells surety bonds, which are used by contractors to guarantee completion of construction projects.
News & Media
BZ is an anticholinergic, similar to atropine or scopolamine, which are used in medicine today.
News & Media
The island is divided up into "boat stations", which are used a reference points.
News & Media
Expert writing Tips
Best practice
When using "which are used", ensure the clause provides essential information, or use "that are used" if the clause is restrictive and critical to the sentence's meaning.
Common error
Avoid substituting "where" for "which" when referring to objects or concepts. "Where" should only be used to refer to places. For instance, the correct usage is "tools which are used", not "tools where are used".
Source & Trust
87%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "which are used" primarily functions as a relative clause, adding descriptive information to a noun. Ludwig AI identifies it as a grammatically correct construction commonly used to provide additional details or context.
Frequent in
News & Media
45%
Science
30%
Encyclopedias
5%
Less common in
Academia
10%
Formal & Business
5%
Reference
0%
Ludwig's WRAP-UP
In summary, "which are used" is a versatile and grammatically sound phrase for adding non-essential information about a noun. As shown by Ludwig AI, it functions as a relative clause and is frequently encountered across diverse fields, including news, science, and encyclopedias. When employing this phrase, remember to use "which" for non-restrictive clauses and "that" for restrictive clauses. Common errors, such as substituting "where" for "which", should be avoided to maintain clarity and precision in writing. Alternatives like "that are employed" can also be considered to add variety.
More alternative expressions(10)
Phrases that express similar concepts, ordered by semantic similarity:
that are employed
Uses a synonym for "used", focusing on the act of employing something for a specific purpose.
that are intended for
Highlights the intended purpose or design of something, rather than just its use.
that serve as
Emphasizes the function or role that something fulfills.
which function as
Similar to 'serve as', but with a stronger emphasis on the operational aspect.
that get utilized
Replaces "used" with "utilized", making it slightly more formal.
which are designed to
Focuses on the design aspect, indicating that something was specifically created for a certain use.
that are applied in
Highlights the application of something in a particular context.
that one can use
Shifts the focus to the possibility or ability to use something.
that are suitable for
Emphasizes the appropriateness or suitability of something for a specific purpose.
that are known for
Highlights a characteristic or property that something is recognised for.
FAQs
How can I use "which are used" in a sentence?
Use "which are used" to add non-essential, descriptive information about a noun. For example, "Smartphones, which are used for communication and entertainment, have become essential in modern life."
What's a more formal alternative to "which are used"?
For a more formal tone, you could use "that are employed" or "which function as", depending on the specific context.
When should I use "that are used" instead of "which are used"?
"That are used" is appropriate when the clause is essential to the meaning of the sentence. "Which are used" is used for non-essential clauses set off by commas. For example, "The tools that are used in this lab are highly specialized."
Are there any synonyms for "used" in the phrase "which are used"?
Yes, you can replace "used" with synonyms such as "employed", "utilized", or "applied" to add variety to your writing.
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
87%
Authority and reliability
4.5/5
Expert rating
Real-world application tested