Defining vs Non-Defining Relative Clauses in Technical English
5 exercises — master the difference between defining and non-defining relative clauses in API docs, technical specs, and engineering communication.
0 / 5 completed
1 / 5
Which sentence correctly uses a defining relative clause to identify a specific API endpoint?
A defining relative clause identifies which specific endpoint is meant (the one that processes payments, not another). It requires no commas. "Which" is acceptable in defining clauses in British English; "that" is also common. Option A incorrectly uses "that" with commas (non-defining with "that" is wrong). Option C is a non-defining clause (adds extra info about an already-identified endpoint). Option D uses "who" for a non-person.
2 / 5
The team lead is describing a specific developer. Which sentence adds non-essential extra information correctly?
Option C is a non-defining relative clause: the developer is already identified (the speaker knows who they mean), and "who joined last month" is additional context, not the identifier. Commas are required. Option D is wrong because "that" cannot be used in non-defining clauses. Options A and B are defining clauses (no commas) — grammatically fine but they imply we need the clause to identify which developer, changing the meaning.
3 / 5
Fill in: "The legacy service _____ was deprecated in v3 still handles 40% of production traffic."
This is a defining relative clause — "that was deprecated in v3" identifies which service we mean (as opposed to others). No commas, and "that" is appropriate for things. "Which" without commas is also acceptable, but "that" is the canonical choice for defining clauses. Option A makes it non-defining (adds commas + which), changing the meaning. Option C uses "who" for a non-person. Option D uses "that" with a comma, which is always incorrect.
4 / 5
Choose the sentence where the relative clause is correctly punctuated as non-defining:
A non-defining relative clause is enclosed by two commas (or a comma and a period at sentence end). Option C correctly wraps ", which was provisioned in Frankfurt," with commas on both sides. Option B is missing the closing comma. Option D misplaces the comma after "which". Option A is a defining clause (no commas) with a different meaning — implying we need the Frankfurt detail to identify which cluster.
5 / 5
Which sentence is most appropriate for formal technical documentation describing a component?
In technical documentation describing a single, already-identified component, a non-defining relative clause (", which...," with commas) is appropriate — the reader knows which module is meant, and the clause provides specification details. Option A is grammatically correct as a defining clause but the phrase "is the one responsible" is redundant and awkward. Option C uses "who" incorrectly. Option D uses "that" with a comma, which is always a grammatical error.