PSAT 10 Grammar Rules Quick Reference

What You Need to Know

PSAT 10 “Grammar” questions (Writing and Language) mostly test whether your sentence is clear, grammatically correct, and logically connected. The fastest way to score is to recognize the handful of rules the test repeats and apply them consistently.

Big idea: Most questions boil down to one of these buckets:

• Sentence structure (run-ons, fragments, correct connectors)
• Punctuation (commas, semicolons, colons, dashes, apostrophes)
• Agreement & verb form (subject–verb, tense, mood)
• Pronouns (case, agreement, clarity)
• Modifiers & parallelism (placement, matching forms)
• Conciseness & precision (no redundancy, correct comparisons)
• Transitions & logic (however/therefore/for example)

Your default strategy: prefer the choice that is grammatical, clear, and concise without changing the meaning.

Step-by-Step Breakdown

Use this quick routine for almost every underlined-portion question:

1. Read the whole sentence (and sometimes the sentence before it). Many “grammar” issues depend on context.
2. Cover the answers and predict what a correct version should do.
3. Identify the rule being tested by spotting what changes across choices:
   • Different punctuation? Likely sentence boundaries or nonessential clauses.
   • Different verb forms? Likely tense, agreement, or verb consistency.
   • Different pronouns? Likely case, agreement, or ambiguity.
   • One choice is much shorter? Likely concision.
4. Check the “big three” first (they eliminate lots of traps):
   • Is it a complete sentence? (no fragment)
   • Are two complete sentences improperly joined? (no run-on/comma splice)
   • Is the meaning logical and unambiguous?
5. Plug in each remaining choice and read it out loud in your head.
6. Choose the most concise option among grammatically correct choices, unless concision causes meaning loss or illogical phrasing.

Mini decision guide (fast)

• If you see comma vs semicolon vs period: ask, “Are there two independent clauses?”
• If you see comma placement around a phrase: ask, “Is this information essential or nonessential?”
• If you see verb changes: find the subject and the timeline.
• If you see pronoun changes: find the antecedent and check case.

Key Formulas, Rules & Facts

Sentence boundaries (independent vs dependent)

Comma splice (wrong): independent clause + comma + independent clause.

• Fix with: semicolon, period, or comma + FANBOYS.

Commas (high-yield rules)

Nonessential test: Remove the phrase. If the sentence still identifies the noun clearly, set it off with two commas (or two dashes, or parentheses).

Common PSAT trap: using only one comma to set off nonessential information. If it starts, it must end.

Semicolons, colons, dashes

Colon test: If you can’t put a period before the colon, the colon is wrong.

Apostrophes (possession vs plural)

• Singular possession: the dog’s leash
• Plural possession: the dogs’ leashes
• Its vs it’s:
  • its = possessive (“its tail”)
  • it’s = “it is”
• Whose vs who’s:
  • whose = possessive
  • who’s = “who is”

Subject–verb agreement

Rule: The verb agrees with the subject, not with words in between.

High-yield traps:

• Prepositional phrases: “The bouquet of roses is…” (subject = bouquet)
• Interrupting clauses: “The students, along with the teacher, are…” (subject = students)
• Either/neither: usually singular (“Neither of the plans works.”)
• Each/every: singular (“Each of the players has…”)
• Collective nouns: usually singular on tests (“The team is…”) unless clearly acting as individuals.

Verb tense & consistency

Simple rule: Don’t change tense unless the timeline changes.

Pronouns: agreement, case, and clarity

Agreement: pronoun must match antecedent in number and person.

• “A student… he or she” is grammatical but often rewritten more cleanly.
• Watch they/their with singular antecedents on standardized tests; the test often prefers matching number.

Case (high yield):

• Subject: I, he, she, we, they
• Object: me, him, her, us, them
• After prepositions, use object: “between you and me”

Quick check: remove the other person.

• “between you and (me)” sounds right; “between you and (I)” does not.

Who vs whom:

• who = subject (who = he)
• whom = object (whom = him)

Clarity: pronoun must clearly refer to one noun.

• If “it/they/this/that” could refer to multiple things, the test prefers replacing it with a specific noun.

Modifiers (placement)

Rule: A modifier must sit next to what it describes.

• Misplaced: “Walking down the street, the trees were beautiful.” (Trees aren’t walking.)
• Fixed: “Walking down the street, I saw beautiful trees.”

Dangling intro modifiers are a favorite PSAT pattern: the noun right after the comma must be the doer.

Parallelism

Comparisons (logical + grammatically correct)

• Compare like with like: people to people, things to things.
• Use than correctly; avoid comparing an item to a whole group that includes it.
  • Better: “Chicago is larger than any other city in Illinois.”

Wordiness, redundancy, and precision

PSAT preference: shortest grammatically correct choice that preserves meaning.

Cut common redundancies:

• “in order to” → “to”
• “due to the fact that” → “because”
• “at this point in time” → “now”
• “each and every” → “each”

Avoid vague “this/that/which” without a clear noun.

Transitions & logical connectors

Choose transitions based on the relationship:

• Contrast: however, nevertheless, on the other hand
• Cause/effect: therefore, thus, consequently
• Addition: furthermore, moreover, also
• Example: for example, for instance
• Sequence: first, next, finally
• Clarification: in other words

Transition questions are about logic, not vibes. Identify whether the second idea supports, contrasts, or concludes the first.

Examples & Applications

Example 1: Fixing a run-on

Sentence: “The experiment failed, the researchers revised the procedure.”

• Both halves are independent clauses.
• Correct fixes:
  • “The experiment failed; the researchers revised the procedure.”
  • “The experiment failed, and the researchers revised the procedure.”
  • “The experiment failed. The researchers revised the procedure.”

Key insight: a comma alone can’t join two complete sentences.

Example 2: Essential vs nonessential clause

Sentence: “The paintings, that were displayed in the front room, attracted many visitors.”

• If the sentence means all the paintings were displayed there (extra info), it should be nonessential:
  • “The paintings, which were displayed in the front room, attracted many visitors.”
• If it means only the specific paintings displayed there (identifying), it’s essential:
  • “The paintings that were displayed in the front room attracted many visitors.” (no commas)

Key insight: commas change meaning; don’t sprinkle them randomly.

Example 3: Pronoun case

Sentence: “The coach spoke to my friend and I after practice.”

• After a preposition (“to”), use object case.
• Test trick: remove “my friend and” → “The coach spoke to me.”
• Correct: “The coach spoke to my friend and me after practice.”

Example 4: Dangling modifier

Sentence: “After reading the article, the main idea seemed clearer.”

• Who read the article? Not “the main idea.”
• Fix by adding the doer:
  • “After reading the article, I found the main idea clearer.”

Key insight: the noun after the comma must be the actor for the intro phrase.

Common Mistakes & Traps

1. Comma Splice: You join two complete sentences with just a comma.

   • Why wrong: commas can’t connect independent clauses alone.
   • Fix: period, semicolon, or comma + FANBOYS.

2. Random Comma Between Subject and Verb: “The result of the trials, was surprising.”

   • Why wrong: you can’t separate a subject from its verb with a comma.
   • Fix: remove the comma unless it’s part of a nonessential interruption with two commas.

3. One-Comma Parenthetical: You open a nonessential phrase with a comma but don’t close it.

   • Why wrong: nonessential info needs two commas (or two dashes, or parentheses).
   • Fix: add the second comma or remove both.

4. Misidentifying Independent Clauses: You use a semicolon/period when the second part isn’t a full sentence.

   • Why wrong: semicolons only join two independent clauses.
   • Fix: use a comma (if dependent) or rewrite the second part into a full clause.

5. Pronoun Ambiguity: “When Maria texted Anna, she was excited.”

   • Why wrong: “she” could be either person.
   • Fix: replace the pronoun with the specific noun.

6. Faulty Parallelism: “She enjoys hiking, to swim, and biking.”

   • Why wrong: list items don’t match form.
   • Fix: keep all gerunds or all infinitives (hiking, swimming, biking).

7. Illogical Comparisons: “The climate of Arizona is drier than Nevada.”

   • Why wrong: climate is compared to a state.
   • Fix: compare climate to climate (“…than that of Nevada”).

8. Over-editing to Sound ‘Formal’: Picking the longest answer with fancy words.

   • Why wrong: PSAT rewards clarity and concision, not stiffness.
   • Fix: choose the simplest correct option that keeps the meaning.

Memory Aids & Quick Tricks

Quick Review Checklist

• Can you spot independent clauses quickly?
• Did you eliminate comma splices and run-ons (period/semicolon/comma+FANBOYS)?
• Are commas used correctly for intro elements, lists, and nonessential info (two commas)?
• Did you avoid a comma between subject and verb?
• Did you check subject–verb agreement by finding the true subject (ignore prepositional phrases)?
• Are verb tenses consistent with the timeline?
• Do pronouns match their antecedents in number/person, use correct case, and remain unambiguous?
• Are modifiers placed next to what they describe (no dangling intros)?
• Is the sentence parallel in lists and paired constructions?
• Are comparisons logical (like with like) and word choice precise?
• If multiple answers are grammatical, did you choose the most concise one that keeps the meaning?
• Did your transition word match the logic (contrast vs cause vs example)?

You don’t need dozens of rules; you need these rules automatic. Run this checklist and you’ll catch most PSAT grammar traps fast.