TOEFL Grammar: Complex Sentence Structures
Practice the complex clause structures that appear frequently in TOEFL reading passages and academic writing.
1. "___ the economy improved, unemployment remained stubbornly high." Which word correctly completes this sentence?
2. Which sentence correctly uses a relative clause?
3. Which sentence correctly uses a participle clause?
4. "It is essential ___ every student submit the form by Friday." Which correctly completes this sentence?
5. Which sentence correctly combines these ideas: "The theory was widely accepted. New evidence later disproved it."
6. "___ the difficulty of the task, the team completed it ahead of schedule." Which word fits?
7. Which sentence uses a noun clause correctly?
8. "The report ___, in fact, was never published." Which correctly completes this sentence with an appositive/parenthetical structure?
9. Which sentence correctly uses an inverted conditional (formal register)?
10. "Not only ___ the hypothesis correct, but it also opened up an entirely new field of research." Which correctly completes this sentence?
Answer key — TOEFL Grammar: Complex Sentence Structures
- A — Although. "Although" correctly introduces a contrast — the economy improved, but unemployment stayed high despite that.
- B — The professor whose research focuses on climate change gave a lecture.. "Whose" is the correct possessive relative pronoun to show the research belongs to the professor.
- B — Having finished the experiment, the team analyzed the results.. The participle clause "Having finished the experiment" must refer to the subject of the main clause — "the team," who did the finishing.
- A — that. "It is essential that" introduces a subjunctive noun clause — the standard structure for this kind of statement.
- A — The theory, which new evidence later disproved, was widely accepted.. "Which" correctly introduces a non-defining relative clause giving extra information about the theory.
- A — Despite. "Despite" is followed by a noun phrase ("the difficulty of the task"), unlike "although," which needs a full clause.
- A — What the scientists discovered surprised the whole field.. "What the scientists discovered" is a correctly formed noun clause acting as the subject of the sentence.
- A — which many considered controversial. "Which" correctly introduces the relative clause referring to "the report" (a thing, not a person).
- A — Had the funding been approved, the project would have proceeded.. "Had the funding been approved" is the correct inverted form of "If the funding had been approved," common in formal academic writing.
- A — was. "Not only" at the start of a sentence requires subject-verb inversion: "Not only was the hypothesis correct..."
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