5 exercises — restrictive vs. non-restrictive relative clauses in technical documentation, specs, and ticket writing.
Quick reference
that — restrictive (defines which one): "The function that returns null…" — no commas
which — non-restrictive (adds extra info): "The Auth module, which uses OAuth…" — commas required
who — for people: "The engineer who reviewed this…"
Test: Remove the clause — if the sentence still identifies the right thing → non-restrictive → use which + commas
0 / 16 completed
1 / 16
Which sentence correctly uses a relative clause to describe a specific technical component? "The module _____ handles authentication should be updated to use the new OAuth library."
Both "which" and "that" are correct for restrictive (defining) relative clauses about things. However, there is a subtle preference: in formal technical writing that is standard for restrictive clauses ("The module that handles authentication"), while which — strictly speaking — introduces non-restrictive clauses ("The Auth Module, which handles OAuth, needs updating"). In practice, especially in American English, that is preferred for restrictive clauses. Use who only for people.
2 / 16
Choose the correct relative pronoun. "The developer _____ submitted the PR left detailed comments explaining every change."
Both "that" and "who" are correct for restrictive clauses about people, though "who" is more formal and standard in professional writing. "Which" is used for things, not people — never say "the developer which submitted". In technical documentation: use who for people (the engineer who…), that/which for systems, processes, and things (the function that…, the endpoint that…).
3 / 16
Which sentence correctly uses a non-restrictive relative clause?
Option B is correct. A non-restrictive (non-defining) relative clause adds extra information about something already uniquely identified — set it off with commas. "The authentication service" is already specific (there's only one), so the clause ", which we deployed last Friday," adds context but doesn't define which service we mean. Option A uses a restrictive clause (no commas) — this implies there are multiple authentication services and we need the clause to specify which one. Option C incorrectly uses "who" for a service. Option D uses "where" (for places).
4 / 16
Complete the technical documentation sentence correctly. "The cache layer, _____ is implemented using Redis, reduces database load by approximately 60%."
"The cache layer, which is implemented using Redis, reduces database load by approximately 60%." — This is a non-restrictive relative clause (notice the commas). Use which for non-restrictive clauses about things. The clause ", which is implemented using Redis," adds a detail about an already-identified layer — it doesn't tell us which cache layer, it tells us something about the one we already know. The quick test: if you can remove the clause without changing the core meaning of the sentence, it's non-restrictive → use which with commas.
5 / 16
You're writing a technical spec. Which sentence is correctly punctuated and uses the right relative pronoun?
"Requests that exceed the rate limit will receive a 429 response." — This is a restrictive relative clause: it specifies which requests we're talking about (only those that exceed the rate limit — not all requests). Restrictive clauses: no commas, use that (or which informally). Option B incorrectly adds commas, turning it non-restrictive — this would imply all requests exceed the limit. Option C (no commas, which) is often acceptable in British English but less standard in technical documentation. Option D has mismatched punctuation (opening comma, no closing comma).
6 / 16
Sarah from the security team flagged a vulnerability in the API gateway. She requested that you update the configuration file to include rate limiting for requests originating from IP address range 192.0.2.0/24. Which sentence best reflects this request, using a relative clause correctly?
This question tests understanding of using 'which' to introduce a relative clause describing a specific object. The incorrect options either use 'that' incorrectly or present the request as a statement rather than a direct instruction using a relative clause. 'Which' correctly refers back to 'the configuration file', specifying *what* needs updating.
7 / 16
Mark is reviewing your pull request for the new user authentication module. He comments: 'The JWT validation logic, which uses the standard library, could be improved for performance.' What does Mark imply about the JWT validation logic?
Mark's comment suggests that the current implementation is acceptable but could potentially be improved. The use of 'which' correctly introduces a clause describing the JWT validation logic. The question tests understanding that relative clauses can provide feedback about existing code without stating a direct requirement for change – it's subtly suggesting optimisation.
8 / 16
You're drafting a technical specification for the new data processing pipeline. Which sentence correctly uses a non-restrictive relative clause to describe the primary component of the pipeline?
This question specifically tests the use of non-restrictive relative clauses. The commas and 'which' indicate that the clause provides additional information about the pipeline but isn't essential to identifying it. Options B and C incorrectly use 'that' or present a redundant statement. Option D is grammatically incorrect.
9 / 16
David from the DevOps team reported a persistent high CPU usage on the application server. He suggested reviewing the configuration for the Nginx reverse proxy. Which sentence best describes his request in a technical document?
This question tests the correct usage of 'which' in a non-restrictive relative clause. The phrase 'which handles incoming requests' is additional information about Nginx and doesn't define it. Note that using an em dash (—) is generally less preferred than commas for this structure, although both are acceptable. Option A incorrectly uses 'that' instead of 'which'. Options C and D lack punctuation.
10 / 16
Elena is writing a Slack message to her team about the recent deployment. She says: 'The new microservice, named Phoenix, has significantly improved response times.' Which relative pronoun is most appropriate in this context?
'That' is the best choice here because 'Phoenix' is a proper noun (the name of the microservice). 'Which' and 'who' are used to refer to people or things generally, not specific names. 'Whose' indicates possession, which isn't relevant in this scenario. Using 'that' avoids unnecessary repetition.
11 / 16
You are writing a pull request description for a change to the authentication module. The original code used an outdated library for generating secure tokens. Which sentence correctly uses a relative clause to explain this?
This question tests the correct use of commas and 'which' to create a non-restrictive relative clause. The phrase 'deprecated in version 2.5' provides additional information about the token generator, not defining it. Using an em dash (—) is acceptable but less common than using commas for this structure.
12 / 16
A software engineer is writing a commit message describing a recent change to the authentication module. Which sentence best reflects this?
This question tests understanding of relative clauses describing *how* a change was made. Option 3 correctly uses 'which' to introduce a clause detailing the positive impact on user experience, aligning with typical technical documentation language. The other options focus on different aspects (refactoring vs. security) without using 'which' effectively.
13 / 16
A developer is documenting a complex API endpoint. Which sentence demonstrates the correct use of a relative clause?
This question focuses on a non-restrictive relative clause. The phrase 'which processes data asynchronously' provides additional information about the endpoint but isn't essential to its definition. Using 'which' correctly introduces an extra detail without altering the core meaning of the sentence. Option A is the correct use.
14 / 16
A system administrator is writing a log entry detailing a recent configuration change. Which sentence correctly utilizes a relative clause?
This question tests the correct use of 'which.' The relative clause provides additional information about the server's configuration. It clarifies *when* the change occurred and its consequence (improved performance). Option 1 is the only grammatically correct sentence using 'which'.
15 / 16
A technical writer is creating a guide for a new feature. Which sentence best utilizes a relative clause to describe a key component?
This question assesses understanding of using 'which' to introduce a descriptive clause. The relative clause 'which stores user data' provides vital information about the database's function, enhancing clarity within the technical documentation. Option 1 demonstrates this correct usage.
16 / 16
A DevOps engineer is explaining a deployment issue to the team via Slack. Which sentence uses a relative clause correctly?
This scenario tests relative clauses in a common communication setting. The clause 'which was overloaded' provides context about the root cause of the deployment issue – specifically explaining *why* the server failed. Using 'which' correctly establishes a causal relationship between the overloaded server and the deployment failure.
What will I practise in "Relative Clauses in Technical Writing — That, Which, Who"?
Practice using restrictive and non-restrictive relative clauses correctly in IT documentation, tickets, and technical writing.
How many exercises are in this module?
This module has 16 multiple-choice exercises, each with instant feedback and a full explanation of the correct answer.
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Every exercise is written by the CoderSlingo team, drawing on real workplace English used in IT roles, then reviewed for accuracy and clarity.