SAT sentence boundaries and punctuation: review and practice

• Decide whether two complete sentences need a period, a semicolon or a comma plus and, but or so.
• Spot a comma splice: two full sentences joined by a comma alone.
• Put matching marks (two commas, two dashes or two parentheses) around extra information in the middle of a sentence.
• Use a colon only after a complete sentence, to introduce an explanation, example or list.
• Recognize when no punctuation belongs at the blank, such as between a subject and its verb.

• Putting a comma between a long subject and its verb. In "The seal on the outer chamber of the tank, cracked," the comma cuts the subject off from cracked. The right answer has no punctuation there.
• Joining two full sentences with a comma alone. "The trial ended, the team left" is a comma splice. Fix it with a period, a semicolon or a comma plus and.
• Using a semicolon before words that can't stand alone. "The team left; because the trial ended" is wrong, since "because the trial ended" is not a sentence.
• Opening extra information with a comma and closing it with a dash, or not closing it at all. If the phrase starts with a comma, it ends with a comma.
• Putting a colon after an incomplete thought. "The kit includes: lenses and filters" is wrong on the SAT. "The kit includes two items: lenses and filters" is fine.
• Picking a period that leaves a fragment. "To test how shade affects water loss." has no main verb, so it can't be its own sentence.

1. Question 1 · Easy

   Entomologist Jolene Lavigne supervises a laboratory devoted to the study of leaf ______ compares the marks that the insects leave on several types of grass. Which choice completes the text so that it conforms to the conventions of Standard English?

   • Abeetles, she
   • Bbeetles. She
   • Cbeetles she
   • Dbeetles. Where she
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   B. Choice B separates the complete statement about Lavigne’s laboratory from the complete statement beginning She compares. Choice A joins them with only a comma; choice C supplies no boundary; choice D makes the second sentence a dependent fragment beginning Where.

2. Question 2 · Easy

   A pinhole camera has no glass lens. Its design relies on a simple optical ______ light passing through a tiny opening travels in straight lines, producing an inverted image on the surface opposite the opening. Which choice completes the text so that it conforms to the conventions of Standard English?

   • Aprinciple,
   • Bprinciple:
   • Cprinciple
   • Dprinciple; because
   Show the answer

   B. The colon follows the complete statement about an optical principle and introduces the clause explaining that principle. Choice A joins independent clauses with only a comma; Choice D leaves a because clause after a semicolon; Choice C joins the clauses without a boundary.

3. Question 3 · Medium

   A tenants’ cooperative introduced a voucher scheme to help members pay for shared repairs. The scheme, devised by the cooperative’s sole founding ______ before the first membership fees were collected, allowed residents to contribute labor in place of cash. Which choice completes the text so that it conforms to the conventions of Standard English?

   • Atreasurer Anika Venkatesh,
   • Btreasurer, Anika Venkatesh,
   • Ctreasurer, Anika Venkatesh
   • Dtreasurer Anika Venkatesh
   Show the answer

   B. Commas on both sides of Anika Venkatesh set off the name supplementing the already complete identifying phrase the cooperative’s sole founding treasurer, while before the first membership fees were collected remains part of the outer description. Choice C omits the name’s closing comma; choice D omits both boundaries; choice A omits its opening comma.

4. Question 4 · Medium

   To examine how shade affects water loss, plant physiologists ______ placed matched seedlings beneath screens of different densities. Over six days, the researchers weighed each pot at dawn and dusk, using covered pots without seedlings to estimate how much water evaporated directly from the soil. Which choice completes the text so that it conforms to the conventions of Standard English?

   • ANasrin Zand, and Kojo Agyeman
   • B: Nasrin Zand and Kojo Agyeman
   • CNasrin Zand and Kojo Agyeman
   • D, Nasrin Zand and Kojo Agyeman,
   Show the answer

   C. Plant physiologists Nasrin Zand and Kojo Agyeman forms one subject whose two identifying names are joined directly by and. Paired commas detach the required names; the comma before and unnecessarily divides a two-name list; the colon follows an unfinished subject.

5. Question 5 · Hard

   Sculptor Reuben Afolayan collected discarded ticket stubs for a work about commuting. The stubs came from routes that had ceased operating ______ he arranged them into an illuminated map whose bright and dark sections corresponded to the former routes. Which choice completes the text so that it conforms to the conventions of Standard English?

   • Ayears earlier, sorting them by the stations that issued them and mounting them on narrow glass strips,
   • Byears earlier. Sorting them by the stations that issued them. Mounting them on narrow glass strips,
   • Cyears earlier. Sorted by the stations that issued them and mounted on narrow glass strips,
   • Dyears earlier. Sorting them by the stations that issued them and mounting them on narrow glass strips,
   Show the answer

   D. Choice D ends the statement with came and makes Sorting and mounting parallel modifiers of he, while that issued them stays inside the description of the stations. Choice A leaves the came and arranged clauses joined only by a comma; choice B strands the Sorting phrase as a sentence fragment; choice C makes the sculptor, rather than the stubs, be sorted and mounted.

6. Question 6 · Hard

   Materials engineer Emi Ishikawa expected a porous tile to absorb a wider range of sound frequencies than a smooth tile made from the same clay. The trial yielded the opposite ______ porous surface absorbed only a narrow band of high frequencies, a cavity behind the smooth tile absorbed a much broader range of frequencies. Which choice completes the text so that it conforms to the conventions of Standard English?

   • Aresult, although the
   • Bresult although the
   • Cresult. The
   • Dresult: although the
   Show the answer

   D. The colon introduces the explanation of the result, and although makes the porous-surface observation subordinate to the main clause about the cavity. Choice A leaves the introduction and that main clause joined by commas; Choice C fixes the outer boundary but leaves the two observations comma-spliced; Choice B adds the concession without establishing a boundary between the introduction and the final main clause.

Ashore's SAT course starts with a 15-minute check that finds the question types costing you the most points, then gives you lessons and practice for each.

• Agreement, Verb Forms, and Modifiers
• Choosing the Precise Word
• Purpose, Structure, and Paired Texts
• Main Ideas and Details
• Using Evidence: Quotes and Data
• Drawing Inferences
• Writing from Notes
• Transitions Between Ideas
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