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Key Takeaways

  • Subject-verb agreement errors are the most commonly tested grammar concept—always identify the true subject.
  • Pronoun errors include unclear antecedents, incorrect case, and agreement issues.
  • Punctuation rules for commas, semicolons, colons, and apostrophes appear frequently on the exam.
  • Sentence structure errors include fragments, run-ons, comma splices, and misplaced modifiers.
  • When in doubt, choose the clearest, most concise option that follows standard written English.
Last updated: January 2026

Grammar, Usage, and Mechanics

Quick Answer: The Praxis Core Writing exam tests your knowledge of standard written English conventions. The most commonly tested areas include subject-verb agreement, pronoun usage, punctuation rules, and sentence structure. Expect 28-34 questions on language and research skills.

Grammar, usage, and mechanics questions make up the majority of the selected-response portion of the Writing subtest. These questions assess your ability to recognize and correct errors in standard written English.

Subject-Verb Agreement

The subject and verb in a sentence must agree in number (singular or plural).

Common Agreement Traps

TrapIncorrect ExampleCorrect Example
Words between subject and verbThe box of chocolates were delicious.The box of chocolates was delicious.
Compound subjects with "or"Either the students or the teacher are responsible.Either the students or the teacher is responsible.
Inverted sentencesThere is many reasons to study.There are many reasons to study.
Collective nounsThe committee have made their decision.The committee has made its decision.
Indefinite pronounsEveryone have finished.Everyone has finished.

Indefinite Pronoun Agreement Chart

Always SingularAlways PluralSingular or Plural
anyone, anyone, eachboth, fewall, any
either, neithermany, severalmore, most
everyone, everybodyothersnone, some
no one, nobody
someone, somebody

Pronoun Usage

Pronouns must agree with their antecedents and be in the correct case.

Pronoun-Antecedent Agreement

IssueIncorrectCorrect
Number agreementA student should bring their textbook.A student should bring his or her textbook. / Students should bring their textbooks.
Gender agreementThe nurse gave his report. (if nurse is female)The nurse gave her report.
Unclear antecedentWhen John met Bill, he was nervous.When John met Bill, John was nervous. / John was nervous when he met Bill.

Pronoun Case

CaseUsePronouns
SubjectiveSubject of verbI, we, you, he, she, it, they, who
ObjectiveObject of verb or prepositionme, us, you, him, her, it, them, whom
PossessiveShows ownershipmy/mine, our/ours, your/yours, his, her/hers, its, their/theirs, whose

Common Case Errors

IncorrectCorrectRule
Him and me went to class.He and I went to class.Subject position requires subjective case
Between you and IBetween you and meObject of preposition requires objective case
It's John who I met.It's John whom I met.Object of verb requires objective case

Punctuation Rules

Comma Usage

RuleExample
Before coordinating conjunction joining independent clausesI studied hard*,* and I passed the test.
After introductory elementsAfter the lecture, students asked questions.
Around nonessential informationMy sister*,* who lives in Boston*,* is a teacher.
In a seriesBring your pencil*,* paper*,* and calculator.
With coordinate adjectivesShe is a dedicated*,* hardworking teacher.

Semicolon Usage

RuleExample
Between independent clauses without a conjunctionI studied hard*;* I passed the test.
Before conjunctive adverbsI studied*;* however*,* I still struggled.
In complex listsSpeakers from Boston, MA*;* Albany, NY*;* and Portland, ME.

Colon Usage

RuleExample
Introduce a list after complete sentenceYou need three items*:* paper, pencil, and eraser.
Introduce an explanationThe reason is clear*:* practice makes perfect.
After salutation in business lettersDear Dr. Smith*:*

Apostrophe Usage

RuleExample
Singular possessiveThe teacher*'s* desk
Plural possessiveThe teachers*'* lounge
Contractionsdon*'t*, it*'s* (it is), who*'s* (who is)
It's vs. ItsIt's raining. / The dog wagged its tail.

Sentence Structure Errors

Fragments

A fragment is an incomplete sentence missing a subject, verb, or complete thought.

FragmentCorrection
Because the test was hard.The test was hard. / I struggled because the test was hard.
Running through the park.She was running through the park.
The book that I read yesterday.The book that I read yesterday was excellent.

Run-On Sentences and Comma Splices

Error TypeExampleCorrection
Run-onI studied hard I passed the testI studied hard*.* I passed the test. / I studied hard*;* I passed the test.
Comma spliceI studied hard, I passed the testI studied hard*,* and I passed the test. / I studied hard*;* I passed the test.

Ways to Correct Run-Ons

  1. Add a period and create two sentences
  2. Add a semicolon
  3. Add a comma and coordinating conjunction (FANBOYS: for, and, nor, but, or, yet, so)
  4. Add a subordinating conjunction

Misplaced and Dangling Modifiers

ErrorIncorrectCorrect
Misplaced modifierShe served sandwiches to the guests on paper plates.She served sandwiches on paper plates to the guests.
Dangling modifierWalking to school, the rain started.Walking to school, I noticed the rain started.
Squinting modifierStudents who study often pass exams.Students who often study pass exams. / Students who study pass exams often.
Test Your Knowledge

Which sentence contains a subject-verb agreement error?

A
B
C
D
Test Your Knowledge

Which sentence uses correct pronoun case?

A
B
C
D
Test Your Knowledge

Which sentence is punctuated correctly?

A
B
C
D
Test Your Knowledge

Which of the following is a complete sentence, not a fragment?

A
B
C
D
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