PSAT 10: Sentence Structure Practice

​Choice A is the best answer. The comma after “far” is needed to separate the introductory prepositional phrase that begins with “with” from the independent clause that begins with “scientists.”

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Choices B, C, and D are incorrect because “though,” “as,” and “and” are conjunctions, and no conjunction is needed between the introductory prepositional phrase and the independent clause that follows.

​Choice C is the best answer. Following the comma after “guitar,” the pronoun “which” is used to begin the relative clause describing what happened to Patton and American music as a result of Sloan’s teaching.

• Choice A is incorrect because “while” wrongly indicates either a contrast between Sloan teaching Patton to play guitar and changing Patton’s life and American music, or that the teaching and changing occurred simultaneously.

• Choice B is incorrect because “so that” wrongly indicates that the purpose of Sloan teaching Patton to play guitar was to result in changing both Patton’s life and American music.

• Choice D is incorrect because “until” wrongly indicates that Sloan taught Patton to play guitar up to the time that doing so changed Patton’s life and American music.

​Choice A is the best answer. The pronoun “who” correctly introduces the relative clause that refers back to the architects and the artist mentioned earlier in the sentence.

• ​​Choice B is incorrect because adding “he” after the comma creates an independent clause. Since the clause that precedes the comma is also independent, this choice results in a comma splice.

• Choice C is incorrect because a conjunction isn’t needed before the pronoun introducing the relative clause.

• Choice D is incorrect because it’s unnecessarily wordy

Choice D is the best answer. The comma after “discourse” is used correctly to separate the introductory dependent clause from the independent clause beginning with “perhaps.” Furthermore, the adverb “perhaps” used after the “if” clause correctly indicates the possibility that engaging youth in civic discourse could cause the numbers of young voters to increase.

• Choice A is incorrect because the conjunction “when” makes the clause after the comma a dependent clause. For the sentence to be grammatically correct, that clause must be independent.

• Choice B is incorrect because “afterwards” doesn’t show the true relationship between the clauses. “Afterwards” indicates a sequence of events that don’t necessarily have a cause-and-effect relationship.

• Choice C is incorrect because a semicolon shouldn’t be used to separate a dependent clause from an independent clause.