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 serves as
Grammar usage guide and real-world examplesUSAGE SUMMARY
"which serves as" is a correct and usable phrase in written English.
You can use it as a conjunction when referring to something that has a certain purpose or fulfills a specific role. For example: "The book, which serves as a guide to the local history, has been popular amongst historians since its publication."
✓ Grammatically correct
Science
News & Media
Formal & Business
Encyclopedias
Wiki
Alternative expressions(17)
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
They are made of fabric grids and a cementitious agent which serves as matrix and binder.
This process uses a metallic material with a resist pattern, which serves as an electrochemical tool.
Science
The resulting groupings are compared to a heuristic visual classification, which serves as a baseline.
Science
These lead to a spacious balcony, which serves as Short's bedroom.
News & Media
frenzies that periodically grip Silicon Valley, one of which serves as the story's quaintly dated milieu.
News & Media
He himself has built a stone walkway around his house, which serves as a fire break.
News & Media
Half.com, which serves as a liaison to collect and disburse payments, would credit her account.
News & Media
Above, a view through the rotunda, which serves as a ceremonial public lobby.
News & Media
The Soyuz, which serves as an emergency lifeboat, is replaced twice a year.
News & Media
CreditTrade, which serves as an exchange for credit derivatives, just turned profitable, John said.
News & Media
At the Guggenheim preview, Moore delivered Jan's poignant love song, which serves as an epilogue.
News & Media
Expert writing Tips
Best practice
Use "which serves as" to clearly define the role or function of a noun in relation to the rest of the sentence. It helps to establish a direct and explicit link between the subject and its purpose.
Common error
Avoid using "which serves as" in simple sentences where a more direct verb could suffice. For example, instead of "The key, which serves as a way to open the door, was lost", try "The key to open the door was lost."
Source & Trust
83%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "which serves as" functions as a relative clause that modifies a noun, providing additional information about its purpose or role. This clause introduces a description of what the noun does or how it is used, as supported by Ludwig's examples.
Frequent in
Science
53%
News & Media
38%
Formal & Business
5%
Less common in
Encyclopedias
2%
Wiki
2%
Reference
0%
Ludwig's WRAP-UP
In summary, "which serves as" is a versatile relative clause used to define the function or purpose of a noun. It is grammatically sound and most frequently encountered in scientific and news contexts. Ludwig AI confirms its correctness and widespread use. When writing, consider whether a more direct verb might be more concise, but otherwise, use it to clearly establish the role or purpose of the subject. Related phrases like "that functions as" can offer slight variations in emphasis.
More alternative expressions(10)
Phrases that express similar concepts, ordered by semantic similarity:
that functions as
Focuses more on the active function or operation performed.
that acts as
Emphasizes the action or behavior of the subject.
that is used for
Highlights the purpose or intended use.
that works as
Similar to "acts as", emphasizing operation.
which is employed as
A more formal alternative, emphasizing utilization.
which is designed to
Focuses on the intended design and purpose.
that provides
Highlights the benefit or contribution of the subject.
which fulfills the role of
A more verbose alternative, emphasizing the specific role.
which constitutes
Emphasizes that something composes or forms something else.
that represents
Highlights the symbolic or indicative nature of the subject.
FAQs
How can I use "which serves as" in a sentence?
Use "which serves as" to specify the function or purpose of something within a sentence. For example, "This document, which serves as a legal agreement, outlines the terms and conditions."
What are some alternatives to "which serves as"?
You can use alternatives like "that functions as", "that acts as", or "that is used for" depending on the context.
Is it correct to use "that serves as" instead of "which serves as"?
While both "that" and "which" can be used as relative pronouns, "which" is generally used for nonrestrictive clauses (adding extra information), whereas "that" is used for restrictive clauses (essential information). Consider whether the information is crucial to understanding the sentence.
What's the difference between "which serves as" and "which acts as"?
"Which serves as" emphasizes purpose or function, while "which acts as" emphasizes behavior or action. The choice depends on whether you want to highlight the intended role or the actual performance.
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
83%
Authority and reliability
4.5/5
Expert rating
Real-world application tested