Master all SAT grammar & punctuation rules with this 2025 cheat sheet. Covers every English Conventions question type, traps, and tips to boost your score.

Why This Matters

On the digital SAT, about 12–15 questions in Reading & Writing test Standard English Conventions — grammar, punctuation, and sentence structure rules of formal written English.
These are the most predictable SAT questions. Master the rules here, and you can lock in easy, fast points that lift your score.

This guide covers every single concept the SAT tests in this domain — from subject–verb agreement to participial phrases, sentence boundaries, and punctuation mastery — plus examples, common traps, and strategies.

Quick-Reference Rule Table

Rule	What to Remember	Example	Common SAT Trap
Subject–Verb Agreement	Verb matches subject in number	The bouquet is lovely.	Prepositional phrase distracts: The bouquet of roses are lovely ❌
Pronoun Agreement	Pronoun matches noun in number and clarity	Each student finished his or her essay.	Using “their” with singular noun without clarity
Pronoun Case	Subject pronouns for doers, object pronouns for receivers	She and I went. / They saw me.	“Me and her went” ❌
Verb Tense Consistency	Keep tenses consistent unless time changes	He studied before he moved.	Unnecessary tense shift mid-sentence
Subjunctive Mood	Use “were” in hypotheticals	If I were you…	Writing “If I was you” ❌
Modifier Placement	Keep modifiers next to what they describe	Running fast, the athlete won.	Dangling: Running fast, the race was won… ❌
Participial Phrases	Adjective phrases starting with -ing/-ed must attach to the right noun	Excited by the news, she smiled.	Attaching to wrong noun
Parallel Structure	Items in lists/comparisons match in form	Hiking, biking, swimming	Hiking, biking, to swim ❌
Sentence Boundaries	Fix run-ons, fragments, comma splices	I left; it was late.	Comma splice: I left, it was late. ❌
Commas	Lists, intros, nonessential info	After dinner, we left.	Random comma between subject and verb
Semicolons	Join two complete sentences	I read; I learned.	Using before dependent clause
Colons	Full sentence before colon	She had one goal: victory.	Colon after incomplete thought
Dashes	One dash = colon; two dashes = parentheses	I love one sport – soccer.	Mixing dash with comma
Apostrophes	Possession or contraction	The student’s book	Mixing plural with possessive
Who / Whom	Who = subject, whom = object	The coach who leads…	Using “whom” as subject
Which / That	Which = nonrestrictive (with commas), That = restrictive (no commas)	The car, which is red…	Wrong clause type
Correlative Conjunctions	Either/or, neither/nor → keep parallel	Either running or biking	Mixing forms
Comparatives & Superlatives	-er/-est or irregular (better, best)	She is better than him	Double comparative: more better ❌
Conjunctive Adverbs	Need semicolon/period before them when joining clauses	I studied; however, I was tired.	Comma splice with “however”

Rule-by-Rule Breakdown with SAT Focus

1. Subject–Verb Agreement

Singular subject → singular verb
Plural subject → plural verb
Ignore words between subject and verb (The box of ornaments is heavy.)
Collective nouns (team, committee) are singular.
“Each” / “Every” → singular
With “or”/“nor” → match verb to nearest subject.

Trap:

The team of engineers were excited. ❌
Correct: The team of engineers was excited. ✅

2. Pronoun Agreement

Match number and person with antecedent.
Keep reference clear — if two nouns could be the antecedent, replace pronoun.

Trap:

When Mia spoke to Ava, she was upset. (Who?) ❌

3. Pronoun Case

Subject pronouns: I, he, she, we, they, who
Object pronouns: me, him, her, us, them, whom
Test: Remove other noun → “I went” ✅, “Me went” ❌.

4. Verb Tense Consistency

Match tense to time clues.
Keep consistent unless timeline changes.
Past perfect (had + verb) for earlier past action.

Example:
By the time she arrived, we had eaten.

5. Subjunctive Mood

Use “were” for unreal hypotheticals: If I were rich…
Use base verb after suggestions/demands: I recommend that he study harder.

6. Modifier Placement

Keep modifiers close to the noun they describe.
Dangling modifier: modifier at start not followed by correct noun.

Example:

Walking down the street, the trees were beautiful. ❌
Walking down the street, she admired the trees. ✅

7. Participial Phrases (FULL)

What they are: Phrases starting with a present participle (-ing) or past participle (-ed, irregular forms) acting as adjectives.
Purpose: Add detail about a noun.
Rule: Must be placed next to the noun they modify.

Present participle example:

Excited by the results, the scientist shared her findings.

Past participle example:

Shocked by the news, he sat in silence.

Common SAT traps:

Dangling participle:
Hiking the trail, the birds chirped loudly. ❌ (The birds didn’t hike.)
Correct: Hiking the trail, we heard birds chirp loudly. ✅
Misplaced participle:
She served sandwiches to the children on paper plates. (Ambiguous — children on plates?)
Correct: She served sandwiches on paper plates to the children.

SAT tip:
If an intro phrase starts with an -ing/-ed word, check that the subject right after it logically performs that action.

8. Parallel Structure

Lists: same grammatical form
Comparisons: compare like with like

Example:
✅ I like swimming, biking, and running.
❌ I like swimming, biking, and to run.

9. Sentence Boundaries

Fragment: Missing subject/verb → Because it rained. ❌
Run-on: Two sentences without proper connection → It rained I stayed inside. ❌
Comma splice: Two sentences joined by just a comma → It rained, I stayed inside. ❌

Fixes:

Period
Semicolon
Comma + FANBOYS (for, and, nor, but, or, yet, so)

10. Commas

Separate items in list
After introductory phrase: After school, we studied.
Around nonessential info: My brother, a doctor, lives in NYC.
❌ Never between subject and verb without reason.

11. Semicolons

Join two independent clauses without conjunction
Before conjunctive adverbs (however, therefore) when joining sentences.

12. Colons

Full sentence before colon
Introduces list, explanation, or quote

13. Dashes

One dash = colon in function
Two dashes = set off extra info
Keep punctuation consistent — don’t mix dash with comma.

14. Apostrophes

Singular possessive: add ’s → the cat’s toy
Plural possessive: add s’ → the cats’ toys
Irregular plural possessive: ’s → children’s books
Contractions: it’s = it is; its = belongs to it

15. Who / Whom

Who = subject of verb
Whom = object of verb/preposition
Test: Replace with he/him → he = who, him = whom.

16. Which / That

Which → nonrestrictive, needs commas: The car, which is red, is fast.
That → restrictive, no commas: The car that is red is fast.

17. Correlative Conjunctions

Either/or, neither/nor, not only/but also → keep elements parallel
Verb agreement matches nearest subject in either/or or neither/nor structures.

18. Comparatives & Superlatives

Two items → comparative (-er, more)
Three+ items → superlative (-est, most)
Irregulars: good → better → best
❌ Never double: more better

19. Conjunctive Adverbs

Words like however, therefore, moreover, consequently
When joining clauses: semicolon before, comma after
I studied; however, I was tired.

20. Adjective vs. Adverb

Adjectives describe nouns/pronouns
Adverbs describe verbs, adjectives, adverbs
❌ He runs quick → ✅ He runs quickly

21. Ellipsis in Comparisons

Maintain grammatical completeness when words are omitted.
I run faster than she [runs].

22. Pronoun Consistency

Stick with “one” or “you” consistently
One should do one’s work.
You should do your work.

Question Types on the SAT

Boundaries – punctuation differences between clauses
Agreement – verb or pronoun changes
Modifier Order – reordering phrases
Punctuation-Only – same words, different marks
Combination – joining sentences without errors

Common SAT Grammar Traps

Choosing what “sounds right” from speech
Missing the true subject (due to extra words)
Lone comma between complete sentences (comma splice)
Apostrophe misuse for plurals/possessives
Parallelism mismatches in lists or comparisons

5-Step Strategy

Spot the rule by comparing choices.
Read the full sentence for clues (timeframe, number, meaning).
Eliminate clear errors (fragments, run-ons, mismatches).
Check remaining for subtle traps.
Plug in & re-read to confirm correctness.

Quick SAT-Style Practice

Q1
Each of the athletes (was / were) excited.
✅ was (Each = singular)

Q2
Excited by the news, (the party began / she began the party) without delay.
✅ she began the party (fixes dangling participle)

Q3
I enjoy reading, painting, and (to cook / cooking).
✅ cooking (parallel gerunds)

Grammar Feedback System

Unlike static prep books, ChatSAT adapts to your performance in real time. When you miss a subject–verb agreement question, it doesn’t just give you the right answer — it explains why the correct choice works, points out the grammar pattern behind it, and then gives you similar SAT-style questions until you can get them right without hesitation. You’ll see exactly which rules you’ve mastered and which still need work.

With built-in timed drills, full-length adaptive practice tests, and an instant feedback engine that mirrors the official SAT format, ChatSAT turns learning grammar from a slow memorization grind into an efficient, results-driven process. Many students using ChatSAT see their Reading & Writing score jump by 50–100 points in just a few weeks because they’re not just practicing — they’re practicing the right way. If you want to walk into test day knowing you’ve seen every rule the SAT can throw at you, ChatSAT is your shortcut.

Final Takeaways

Memorize these rules — the SAT repeats them.
Practice in the official Bluebook app for real question styles.
Focus on accuracy first, then speed.
For maximum points: know the common traps and check for modifier placement every time.