Most Common SAT Grammar Mistakes
Subject-verb agreement
The verb must match the true subject, not a nearby noun. Prepositional phrases and clauses between subject and verb are the usual trap.
Example
Wrong: The group of students are ready. Right: The group of students is ready.
Practice move: Identify the subject, cross out prepositional phrases, then choose the verb form.
Pronoun clarity and agreement
Every pronoun needs a clear antecedent and must agree in number. Vague "they" or "it" references cost points when multiple nouns are nearby.
Example
Wrong: When Sarah met Emma, she was nervous. (Who was nervous?) Right: Sarah was nervous when she met Emma.
Practice move: Replace the pronoun with the noun it should refer to; if the sentence is unclear, rewrite.
Verb tense and consistency
Tense should follow the timeline in the sentence. Unnecessary shifts between past and present confuse meaning.
Example
Wrong: She walked into the room and sits down. Right: She walked into the room and sat down.
Practice move: Mark time clues (yesterday, now, before) and lock one primary tense per sentence.
Comma splices and run-ons
Two independent clauses cannot be joined with only a comma. You need a period, semicolon, or conjunction.
Example
Wrong: The experiment failed, we revised the method. Right: The experiment failed, so we revised the method.
Practice move: Read each side of the comma as its own sentence; if both stand alone, add a conjunction or split them.
Misplaced and dangling modifiers
Descriptive phrases must sit next to what they modify. Opening modifiers should name the doer clearly.
Example
Wrong: Running to class, the backpack bounced. Right: Running to class, Maya secured her backpack.
Practice move: Ask who performed the action in the opening phrase; that noun should follow immediately.
Faulty parallelism
Items in a list or comparison must share the same grammatical form.
Example
Wrong: She likes hiking, to swim, and biking. Right: She likes hiking, swimming, and biking.
Practice move: Underline each list item and check that all are nouns, infinitives, or gerunds consistently.
Wordiness and redundancy
SAT grammar often prefers the shortest clear option. Redundant pairs and filler phrases are common wrong answers.
Example
Wrong: due to the fact that → Right: because
Practice move: When two answers mean the same thing, test which version says it in fewer words without losing meaning.