10 original Boundaries questions, easiest first. Where sentences end, and which punctuation may join what. Answer them all, then submit once to see every answer explained.
Although the clinical trial produced promising preliminary data the research team cautioned that regulatory approval could still take several more years.
Which choice fixes the punctuation error?
C — data, the research team. 'Although the clinical trial produced promising preliminary data' is a dependent introductory clause that requires a comma before the main clause begins. Choice C correctly adds this comma.
Despite weeks of exhaustive rehearsal the opening night performance was cancelled after a sudden power outage at the theater.
Which choice fixes the punctuation error?
D — rehearsal, the opening. 'Despite weeks of exhaustive rehearsal' is an introductory phrase that requires a comma before the main clause. Choice D correctly adds this comma; a semicolon or colon would be used to join independent clauses or introduce a list/explanation, neither of which applies here.
The bakery's menu lists four specialty breads, however, only two are available on weekdays.
Which choice fixes the sentence boundary error?
B — breads; however, only. 'However' here connects two independent clauses and needs a semicolon (or period) before it, with a comma after. Choice B correctly uses a semicolon before 'however' and a comma after it, fixing the comma splice in the original.
The county's oldest bridge closed for structural repairs last month, it will reopen sometime before the harvest season begins.
Which choice fixes the sentence boundary error?
C — month. It. The original is a comma splice joining two independent clauses with only a comma. Choice C correctly separates them into two sentences with a period; choice D adds an unnecessary comma after 'and.'
Volunteers spent the afternoon painting the fence trimming the hedges, and weeding the flower beds.
Which choice fixes the punctuation error?
B — fence, trimming. This sentence contains a list of three parallel gerund phrases ('painting the fence,' 'trimming the hedges,' 'weeding the flower beds') that must be separated by commas throughout. Choice B adds the missing comma after 'fence' to match the comma already present after 'hedges.'
Despite months of careful planning the charity gala was postponed after the venue suffered unexpected water damage.
Which choice fixes the punctuation error?
D — planning, the charity. 'Despite months of careful planning' is an introductory phrase that requires a comma before the main clause. Choice D correctly adds this comma; a semicolon or colon would be used to join independent clauses or introduce a list/explanation, neither of which applies here.
The pavilion, which was rebuilt in 2015 remains a popular gathering spot for the annual harvest festival.
Which choice fixes the punctuation error?
C — 2015, remains. 'Which was rebuilt in 2015' is a nonrestrictive clause set off by a comma after 'pavilion,' and requires a matching comma before 'remains' to properly close the interruption. Choice C supplies this.
The diner's menu lists six daily specials, however, only two remain available after 2 p.m.
Which choice fixes the sentence boundary error?
C — specials; however, only. 'However' here connects two independent clauses and needs a semicolon (or period) before it, with a comma after. Choice C correctly uses a semicolon before 'however' and a comma after it, fixing the comma splice in the original.
Grace Hopper whose work helped develop early computer programming languages remains a celebrated figure in computing history.
Which choice fixes the punctuation error?
D — Hopper, whose work helped develop early computer programming languages,. 'Whose work helped develop early computer programming languages' is a nonrestrictive clause that must be set off by commas on both sides. Choice D correctly adds commas both before 'whose' and after 'languages.'
The novel's structure alternates between four narrators, a retired sailor, his estranged daughter, a young dockworker, and an unnamed observer.
Which choice fixes the punctuation error?
B — narrators: a. A colon correctly introduces the list of four narrators following the complete independent clause 'The novel's structure alternates between four narrators.' A comma or semicolon would not properly perform this function.
Score:
Every question above is now marked up: the correct answer is highlighted, any wrong option you picked is flagged, and each explanation is open.
No. Every question here is original, written to the College Board's published Digital SAT Reading & Writing specification for the Boundaries skill. No retired or copyrighted College Board material appears anywhere on this site.
Boundaries tests sentence boundaries and the punctuation that marks them: periods, semicolons, colons, commas, and dashes, including comma splices, run-ons and the punctuation around supplementary elements. Every question is answerable from the sentence in front of you, without knowing anything about the subject matter.
Ignore how the sentence sounds and test the structure instead. Decide whether the material on each side of the punctuation is an independent clause — a subject and a verb that could stand alone. Two independent clauses need a period, a semicolon, or a comma plus a coordinating conjunction; a colon needs an independent clause on its left; a supplementary phrase needs the same mark on both sides, and never a comma on one side and a dash on the other.
No, and deliberately so. This drill is 10 Boundaries questions back to back; a real Reading & Writing module is 27 questions in 32 minutes drawn from all eleven skills. Use a drill to fix one weakness, then take a full module to practice the real thing.
No. The SAT has no penalty for a wrong answer — a blank and a wrong guess both score zero — so answer every question, including the ones you have to guess.