Digital SAT Prep · Digital SAT Reading, Writing & Math
Standard English Conventions (Writing)
Sentence structure, usage and punctuation editing under boundaries and form.
Eight conventions decisions the Digital SAT Writing side drills under time pressure — where a sentence ends, which noun owns the verb, which commas mark a side note — not a parts-of-speech catalogue.
- Digital SAT Prep
- Medium level
- 8 concepts
- 5 practice questions
1A comma alone cannot join two independent clauses
An independent clause can stand as its own sentence: it has a subject and a finite verb and states a complete idea. When two such clauses meet, a bare comma is a comma splice — illegal on the Digital SAT. Legal joins are a period, a semicolon, or a comma plus a coordinating conjunction (for, and, nor, but, or, yet, so — FANBOYS).
The fastest check: replace the disputed mark with a period. If both sides still read as full sentences, a lone comma is wrong. A coordinating conjunction without the comma (and a fused run-on with no mark at all) are also wrong when both sides are independent.
Figure. Two full clauses need a period, a semicolon, or comma + FANBOYS — never a bare comma.
Boundary check
- Split at the markRead each side of the punctuation as if it ended with a period.
- Ask independenceIf both sides are full sentences, you need a period, a semicolon, or comma + FANBOYS — never a comma alone.
- Pick the legal joinChoose the option that supplies one of those three; reject splice and run-on choices.
| Mark | Legal? | Cue |
|---|---|---|
| period | Yes | Two separate sentences |
| semicolon | Yes | Closely related independents; no conjunction required |
| comma + FANBOYS | Yes | and / but / so… must be present with the comma |
| comma alone | No — splice | Both sides still full sentences |
| no mark / bare and | No — run-on | Independents smashed together |
Choose the best punctuation: The experiment failed the first time ___ the researchers refined their method and tried again.
- time, the
- time; the
- time the
- time and the
Both sides are independent clauses. time; the joins them with a semicolon. time, the is a comma splice. time the is a run-on. time and the coordinates with and but omits the required comma before the FANBOYS join of two independents.
2A colon needs a complete clause before it
On the Digital SAT, a colon introduces an explanation, elaboration, or list — but only after a clause that could stand alone. The lab confirmed one result: the catalyst was inert is legal because The lab confirmed one result is independent. Confirmed one result: the catalyst was inert is not: the words before the colon are a fragment.
Do not use a colon to glue two independents the way a semicolon does when you only need a soft join with no introduce-what-follows job. If the blank is between two full sentences and no introduction is happening, prefer a period or semicolon.
Figure. A colon is legal only when the words before it form a complete independent clause.
Colon test
- Read left of the colonAsk whether those words form a complete independent clause by themselves.
- Check the jobConfirm the right side explains, lists, or elaborates what the left side announced.
- Reject fragment introsIf the left side is missing a subject or finite verb, drop the colon option.
Which sentence uses the colon correctly?
- The committee reviewed: three proposals before noon.
- The committee reviewed three proposals: a bridge plan, a park redesign, and a transit study.
- The committee reviewed three proposals: and then adjourned.
- Reviewed three proposals: a bridge plan, a park redesign, and a transit study.
Option B places a colon after a complete clause and introduces a list. Option A splits verb from object with a colon. Option C puts and then adjourned after a colon that promised elaboration of the proposals. Option D leaves a fragment before the colon.
3Intervening phrases do not set the verb
The verb agrees with the true subject, not with a noun that sits nearer the verb inside a modifier. In The collection of rare stamps is displayed in the main hall, the subject is collection; of rare stamps is a prepositional phrase and never controls number. Along with, as well as, together with and with tags work the same way: The director, along with the interns, arrives early — director stays singular.
Stems plant a plural noun in the intervening phrase on purpose. Cross out the of-phrase or along-with tag before you choose is/are or was/were; what remains owns the verb.
Figure. Strip the of-phrase; the verb tracks the head subject, not the nearer plural noun.
Find the owner
- Strip the phraseDelete of + noun, along with…, as well as…, together with…, and with… so the head subject stands alone.
- Read its numberDecide singular or plural for that bare subject — collection and director are singular.
- Match the verbPick is/are or was/were to match that number; ignore every noun you crossed out.
Select the correct verb: The collection of rare stamps ______ displayed in the main hall.
- are
- were
- is
- have been
The true subject is collection (singular). Of rare stamps is an intervening prepositional phrase. Is matches collection. Are, were and have been all agree with stamps, the planted nearer noun.
4Pronouns must match a clear antecedent in number
A pronoun takes the number of its antecedent. Singular antecedents (student, company, each applicant) take singular pronouns in Digital SAT American usage: Each applicant must submit a portfolio before the deadline — not their when the stem is testing agreement and a singular option is offered. Collective nouns such as committee, team and jury usually take singular pronouns when the group acts as one unit.
Ambiguity is an error class of its own. If a pronoun could point at two nouns, the sentence is broken even when number matches one of them. Prefer the option that names the noun again or rewrites so only one antecedent is possible.
Figure. Pronoun number follows a clear singular antecedent; Digital SAT American usage keeps each with singular forms.
Antecedent first
- Name the nounFind the word the pronoun is supposed to replace — not the nearest noun by accident.
- Match numberSingular antecedent → singular pronoun; plural → plural. Treat committee/team as singular when they act as one unit.
- Kill ambiguityIf two nouns compete, pick the rewrite that leaves only one possible antecedent.
| Antecedent | Usual SAT pronoun | Planted trap |
|---|---|---|
| each / every + noun | singular (he/she/his/her/its — or rewrite) | plural their/they from the of-phrase noun |
| company / university / committee (as unit) | it / its | they / their as if naming the members |
| two possible nouns before the pronoun | rewrite to name the noun | keeping a grammatical but unclear it/they |
Choose the best version: The committee submitted ______ final report on Monday.
- their
- its
- it's
- there
Committee acting as one unit takes singular its in American SAT usage. Their treats the members as plural. It's is the contraction it is, not a possessive. There is an adverb/placeholder, not a possessive determiner.
5Nonessential modifiers take a paired mark; essential ones take none
Nonessential (parenthetical) information can be removed without changing who or what you mean. It takes a matching pair of commas, dashes, or parentheses: My sister, who lives in Austin, is visiting — the who-clause is extra. Essential (defining) information identifies which one and takes no commas: Students who live on campus must renew housing — drop the who-clause and the meaning changes.
A single comma that opens a nonessential clause without closing it is wrong. So is wrapping an essential clause in commas as if it were a side note. Match the mark type on both sides when a pair is required — do not open with a comma and close with a dash.
Figure. If deleting the clause still leaves a clear noun, wrap it in a matched pair; if it defines which one, use no commas.
Delete test
- Delete the clauseRead the sentence without the modifier. If the remaining noun is still uniquely clear, the clause was nonessential.
- Pair or bareNonessential → commas/dashes/parentheses on both sides. Essential → no commas.
- Match the pairIf you open with a comma, close with a comma — not a dash or nothing.
| Type | Delete test | Punctuation |
|---|---|---|
| Nonessential | Meaning of the noun stays clear | Paired commas, dashes, or parentheses |
| Essential / defining | Which one? becomes unclear | No commas around the clause |
| Broken pair | Opens but never closes (or mixed marks) | Illegal — fix to a matched pair or none |
Choose the correctly punctuated sentence.
- The first novel, that won the prize was later filmed.
- The first novel that won the prize was later filmed.
- The first novel that won the prize, was later filmed.
- The first novel, that won the prize, was later filmed.
That won the prize defines which novel — essential — so it takes no commas (B). A wraps only the left side. C inserts a banned comma between subject and verb. D treats a defining that-clause as parenthetical; on SAT keys, that-clauses used to define are essential and stay bare.
6Do not park a comma between subject and verb
A single comma must not split a subject from its verb, or a verb from its object, when nothing parenthetical sits between them. The researchers who finished early, published their data is wrong — researchers…published needs no comma. The same ban hits The study examined, three coastal sites.
Commas that look like a breath pause are still wrong if they sever that core link. The legal commas nearby are pairs around a true nonessential insert: The researchers, who finished early, published their data — both commas required because the who-clause is extra.
Figure. A single comma must not split subject from verb; only a paired wrap around a true insert is legal.
Core link
- Find S and VUnderline the subject head and its finite verb (and the verb’s object if choices put a comma there).
- Ask what sits betweenIf only a restrictive clause or nothing sits between them, reject a lone interrupting comma.
- Allow only pairsKeep commas solely when a removable nonessential element is wrapped on both sides.
Choose the best version: The data that the lab collected ___ published last spring.
- collected, were
- collected were
- collected; were
- collected: were
Data…were is subject and verb; that the lab collected is essential and takes no wrapping commas, so no comma before were (B). collected, were inserts a banned subject–verb comma. Semicolon and colon falsely treat were published as a new independent clause.
7Verb tense must follow the passage’s time frame
Within a short Digital SAT stem, verbs should stay in the time frame the surrounding sentences already established unless a clear time cue shifts it. If the passage narrates a completed past study (measured, found, concluded), a sudden present reveals or future will reveal usually breaks continuity.
Shift only when the meaning demands it: a general truth may stay present beside a past experiment (The chemists measured the rate; water boils at 100°C at standard pressure), or an earlier past may need past perfect (had measured) against a later past. Blind matching of the nearest verb without reading the cue is how tense traps win.
Figure. Match neighbouring tense unless a clear time cue licenses a shift.
Time-frame check
- Map the frameSkim neighbouring verbs and time words (in 2019, previously, now, by then).
- Prefer continuityDefault to the established tense when no cue licenses a shift.
- Allow licensed shiftsKeep present for timeless facts, or past perfect for the earlier of two pasts, only when the meaning needs it.
In 2018 the team isolated the compound and ______ its structure within a month.
- determines
- will determine
- determined
- is determining
In 2018 plus isolated sets a completed past narrative, so determined continues that frame. Determines and is determining jump to present. Will determine jumps to future with no cue.
8A modifier must attach to the thing it describes
Opening phrases and other modifiers grab the nearest grammatical head. Walking into the lab, the samples were already labeled wrongly makes Walking modify samples — samples do not walk. Walking into the lab, the chemist found the samples already labeled puts chemist next to the phrase so the modifier attaches correctly.
The same attachment rule governs which / that clauses and appositives: place them beside the noun they describe. When choices rearrange word order, pick the version that leaves no dangling or squinting modifier — not the version that merely sounds formal.
Figure. An opening modifier grabs the nearest grammatical head — put the right noun beside it.
Attach the modifier
- Name what it describesFrom meaning, say which noun or pronoun the modifier is about.
- Check the neighbourConfirm that noun sits in the grammatical slot the modifier actually touches.
- Rewrite if danglingChoose the option that puts the right head beside the phrase; reject versions that make the wrong noun the neighbour.
Choose the best version.
- Rushing to meet the deadline, the report was submitted incomplete.
- Rushing to meet the deadline, the intern submitted an incomplete report.
- Rushing to meet the deadline, an incomplete report was submitted by the intern.
- The report was submitted incomplete, rushing to meet the deadline.
Rushing… must modify whoever rushed. B puts the intern beside the phrase. A and C make the report / an incomplete report the grammatical neighbour. D leaves a trailing dangling phrase with no clear head.
Notes
- Sentence Boundaries: Two independent clauses cannot be joined by a comma alone (comma splice); use a period, semicolon, or comma plus a coordinating conjunction (FANBOYS).
- Subject-Verb Agreement: The verb must agree with its true subject even when prepositional phrases or clauses intervene, e.g., 'The box of tools is heavy.'
- Pronoun-Antecedent Agreement: Singular antecedents take singular pronouns; collective nouns like 'committee' are usually singular in American usage.
- Punctuating Modifiers: Nonessential (parenthetical) information takes a pair of commas, dashes, or parentheses, while essential information takes no commas.
Formulas
- Independent + Independent: join with ; or , + FANBOYS or split with a period; never comma alone.
- No comma between a subject and its verb, or between a verb and its object.
- Nonessential element = commas on both sides; essential (defining) clause = no commas.
- Verb tense/number: match the verb to the subject's number and to the passage's established time frame.
Exam traps & shortcuts
- To test a comma splice, replace the punctuation with a period; if both sides stand alone as sentences, a comma is wrong.
- Cross out prepositional phrases between subject and verb to expose the real subject before choosing the verb form.
- If choices differ only in punctuation, first decide whether each side of the mark is an independent clause, then apply the boundary rule.
Reference tables
Run the boundary test before browsing punctuation cosmetics; run the owner test before picking a verb or pronoun.
| Decision | Do this | Reject |
|---|---|---|
| Boundaries | Period-test each side; join independents with . ; or , + FANBOYS | Bare comma splice or unmarked run-on |
| Colon | Complete clause on the left; list/explain on the right | Colon after a fragment |
| Subject–verb | Cross out intervening of-/along-with phrases; agree with the head | Verb matching the nearer noun in the phrase |
| Pronoun | Match number; keep antecedent unique | Their for singular committee; unclear it/they |
| Commas | Pair around nonessential; none around essential; never split S|V | One-sided comma; breath-pause between subject and verb |
| Tense / modifier | Keep the passage frame; put the described noun beside the phrase | Uncued tense jump; dangling opener |
Recap
Keep these on exam day; each one kills a planted conventions distractor.
- Splice
- Two independents need a period, a semicolon, or comma + FANBOYS — never a comma alone.
- Colon
- Left of a colon must be a complete clause that the right side explains or lists.
- Owner
- Intervening phrase never sets the verb — collection of stamps is.
- Pronoun
- Singular antecedent → singular pronoun; committee as a unit → its.
- Commas
- Nonessential = paired marks; essential = none; never a lone S|V split.
- Attach
- Opening phrase modifies the nearest head — put the right noun there.
Practise Standard English Conventions (Writing)
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