SAT Boundaries Questions
Where sentences start and stop. Commas, semicolons, colons and dashes, and whether you have joined two complete sentences legally.
In short
- Boundaries is part of Standard English Conventions, about 26% of the scored Reading and Writing questions: 11 to 15 on every test.
- Standard English Conventions questions come third in every Reading and Writing module, arranged from easiest to hardest whichever rule they test.
- Colon vs. dash punctuation is the trap Rivie's practice tests set most often in Boundaries questions.
Common traps
Most common first, from Rivie's ten practice tests.
Colon vs. dash punctuation
Punctuation pivot at a clause boundary; the wrong choice mixes a colon and a dash, or uses one where the other is needed (or where a comma would suffice).
The usual mistake: You sense a 'pause' is needed and pick whichever heavy mark looks elegant. The right call depends on whether the second part defines, extends, or interrupts.
Finite verb missing
Sentence boundary error: the wrong choice produces a fragment by leaving the sentence with only a participle (-ing or -ed) and no main verb.
The usual mistake: You read a long fragment and assume it's grammatical because it sounds like a sentence, without checking that there's a tensed verb attached to the subject.
Comma splice
Two independent clauses joined by only a comma. Fix is a semicolon, period, or comma + FANBOYS conjunction.
The usual mistake: You hear the natural pause and pick a comma, the same intuition that creates comma splices in your own writing.
Introductory clause comma
An introductory clause or long phrase before the main subject takes a comma after it; without the comma the main clause runs into the intro and the sentence misreads.
The usual mistake: You judge by feel: short intros sound fine without a comma. The rule is mechanical: any prepositional phrase or subordinate clause BEFORE the subject takes a comma.
Unmatched dash
Em dashes used parenthetically must come in pairs; a dash that opens a mid-sentence aside must close with another dash, not a comma.
The usual mistake: You see one dash and don't track whether the aside it opened ever closes. The trap is a sentence that uses a dash mid-clause and then a comma to return: broken pairing.
Combining sentences
Two independent clauses join with (a) a period, (b) a semicolon, (c) a comma plus a FANBOYS conjunction, or (d) a colon if the second amplifies the first. Anything else is a comma splice or run-on.
The usual mistake: You pick the choice with a comma between two independent clauses because it 'flows' better. The grammar isn't asking for flow; it's asking for one of the four legal joins.
Try a question
From Rivie's practice tests. Pick an answer to see why it is right or wrong.
The curator noted three separate influences on the painter's early style ____ the late-Gothic altarpieces of his hometown, the Flemish portraits he studied in Antwerp, and a brief apprenticeship with an Italian miniaturist. Which choice completes the text so that it conforms to the conventions of Standard English?
Video lessons
Free on YouTube, picked for this topic.