C1 Advanced Relative & Nominal Clauses – Test 1 IELTS, TOEFL & YDS Grammar Practice EnglishTestCenter
Practice C1 Advanced Relative and Nominal Clauses with 15 challenging multiple-choice questions. Perfect for IELTS, TOEFL, and YDS preparation with extremely detailed explanations.
At C1 level, learners are expected to demonstrate sophisticated control of relative clauses (defining, non-defining, reduced, preposition + relative pronoun structures) and nominal clauses (that-clauses, whether/if clauses, wh-clauses functioning as subjects, objects, and complements).
In high-stakes exams such as IELTS, TOEFL, and YDS, advanced clause structures are frequently tested because they reflect academic precision, syntactic flexibility, and formal writing competence.
This test includes reduced clauses, formal preposition placement, subject clauses, object clauses, embedded questions, and nominal relative clauses.
Instructions: Choose the best answer for each question.
RESULTS
#1. The researcher, ______ work has been widely cited, will deliver the keynote speech.
#2. The proposal to ______ they objected was eventually revised.
#3. What the committee ultimately decides ______ yet to be announced.
#4. The students were unable to determine ______ the results were accurate.
#5. The theory, ______ was once widely accepted, has now been challenged.
#6. She explained the reasons for ______ she had declined the offer.
#7. The candidate presented a solution, the details of ______ were highly innovative.
#8. ______ he failed to disclose was later discovered during the investigation.
#9. The report raises questions about the criteria ______ were used in the selection process.
#10. It remains unclear ______ the policy will be implemented this year.
#11. The author proposes a framework ______ aims to integrate multiple perspectives.
#12. The issue is not ______ the policy is necessary, but how it should be enforced.
#13. The scientist, many of ______ colleagues supported the hypothesis, received international recognition.
#14. ______ the data suggest contradicts the initial assumption.
#15. The university has introduced new regulations, compliance with ______ is mandatory.
Detailed Explanations (All Answers Explained Together)
Below are extremely detailed explanations for all correct answers. Each explanation focuses on grammatical function, clause type, agreement, formality, and advanced C1-level usage. Only the correct answer word is referenced.
1. whose
This sentence requires a possessive relative pronoun because “work” belongs to the researcher. At C1 level, learners must distinguish between subject/object relative pronouns and possessive forms. “Whose” correctly expresses possession and functions within a non-defining relative clause separated by commas.
2. which
When a preposition appears before a relative pronoun in formal English, only “which” (or “whom” for people) is grammatically correct. This is a highly formal C1 structure: “to which they objected.” The conjunction “that” cannot follow a preposition in this structure.
3. is
“What the committee ultimately decides” is a nominal clause functioning as a singular subject. Even though “decides” refers to an action, the entire clause is treated as a singular entity. Therefore, subject-verb agreement requires the singular verb “is.”
4. whether
After verbs expressing uncertainty such as “determine,” a nominal clause introduced by “whether” is required when presenting alternatives or doubt. At advanced level, learners must know that “whether” is more formal and appropriate than “if” in many academic contexts, especially when the clause functions as an object.
5. which
Non-defining relative clauses require “which” when referring to things. The commas signal additional information rather than essential identification. “That” is not typically used in non-defining clauses in formal English.
6. why
After “reasons for,” the relative word introducing the clause is “why.” This forms a relative clause explaining reasons. Although “which” is possible in some contexts, the idiomatic and grammatically expected form here is “why.”
7. which
The phrase “the details of which” demonstrates an advanced preposition + relative pronoun structure. This structure avoids repetition and maintains formal tone. Only “which” can follow the preposition “of” in this construction.
8. What
“What he failed to disclose” is a nominal relative clause functioning as the subject of the sentence. “What” combines the meaning of “the thing that.” This structure is typical at advanced level and requires careful distinction from “that.”
9. which
The relative clause modifies “criteria,” which refers to things, not people. Therefore, “which” is required as the subject of the relative clause. Agreement is maintained because “criteria” is plural.
10. whether
After expressions like “It remains unclear,” the formal conjunction introducing uncertainty is “whether.” At C1 level, learners must recognize that “whether” is preferred in formal academic writing, particularly in subject or complement clauses.
11. which
The clause “which aims to integrate multiple perspectives” modifies “framework.” Since it refers to a thing and functions as a defining clause, “which” is grammatically appropriate.
12. whether
In correlative structures such as “not whether… but how…,” the conjunction “whether” introduces a nominal clause. This pattern requires parallelism and formal structure typical of academic English.
13. whose
This sentence demonstrates possession within a complex non-defining clause: “many of whose colleagues.” “Whose” correctly expresses the relationship between the scientist and colleagues. This structure is common in advanced academic texts.
14. What
“What the data suggest” forms a nominal clause functioning as the subject of the sentence. The entire clause is treated as a singular concept. This advanced construction requires understanding that “what” means “the thing that.”
15. which
“Compliance with which” is another formal preposition + relative pronoun construction. Only “which” can follow the preposition “with.” This structure is frequently found in legal and academic writing and reflects advanced syntactic control.
