SAT and ACT Grammar Rules and Punctuation

Note: These rules have been updated for the digital SAT.

Resources for Further Learning

• Question of the Day: Get tips and strategies to ace your exam.
• Books:
  • The Ultimate Guide to SAT Grammar
  • The Complete Guide to ACT English

1. Periods & Semicolons

• Semicolon = Period: These are interchangeable on SAT and ACT.
• Used between two complete sentences.
  • Example: "London is an old city; it has many new buildings."
• Before conjunctive adverbs like however, therefore at the beginning of a clause.
  • Example: "London is an old city; however, it has many new buildings."
• Note:
  • Read sentences fully to avoid missing sentence boundaries.
  • Watch for sentence boundary errors.

2. Colons and Dashes

• Used to introduce lists and explanations.
• Follow a full sentence that sets up the following information.
• Colons are more frequently tested than single dashes.
• Example:
  • Before list: "Visitors to London often spend their time in three main types of attractions: museums, castles, and shops."
  • Before explanation: "When the Manchus took control of China, the Great Wall lost its protective purpose: the Chinese empire now extended well north of the wall."

3. Comma + FANBOYS

• Comma + FANBOYS = Period = Semicolon for complete sentences.
• Comma Splices: Joining two sentences with a comma is incorrect.
  • Example: "London is a very old city, it has some extremely modern parts." (Incorrect)
  • Corrected: "London is a very old city. It has some extremely modern parts."
• Comma + FANBOYS + Verb = WRONG if the subject is the same and doesn't repeat.

4. Commas & Dependent Clauses

• Dependent Clauses cannot stand alone.
• Use a comma when the dependent clause precedes an independent clause.
  • Example: "Because London is a very old city, it has buildings from many different eras."

5. Transitional Words & Phrases

• Questions may ask for the most logical transition.
• Types of Transitions:
  • Continuers: Add similar ideas.
  • Cause-and-effect: Indicate results.
  • Contradictors: Signal opposing ideas.
• Use context to determine the relationship between sentences.

6. Non-Essential Information

• Can be removed without affecting sentence meaning.
• Punctuation:
  • Two Commas, Two Dashes, or Two Parentheses.
  • Do not mix punctuation types.

7. Commas with Names & Titles

• Determine if the name/title is essential:
  • No commas if essential.
  • Two commas if non-essential.
• Check if the sentence still makes sense without the name/title.

8. Additional Comma Uses & Misuses

• Correct Uses:
  • Separate items in a list.
  • Separate reversible adjectives.
• Incorrect Uses:
  • Before/after prepositions, subjects and verbs, or compound items.
  • Before or after "that".

9. Apostrophes (Plural vs. Possessive)

• Apostrophe = Possessive; No apostrophe = Plural.
• Nouns: Singular possessives add -s (e.g., the cell's DNA).
• Pronouns: No apostrophe for possessive (e.g., its = possessive).

10. Pronouns & Nouns

• Agreement: Match singular/plural forms.
• People vs. Things: Who(m) = people; which = things.
• Who vs. Whom: Whom after a preposition is correct.

11. Subject-Verb Agreement

• Singular 3rd Person Verbs end in -s; plural do not.
• Compound Subject = Plural.
• Prepositional Phrases between subject and verb can distract.
• Each/Every = Singular.

12. Verb Tense

• Consistency: Keep tense consistent within paragraphs.
• Present Perfect: has/have + verb for actions continuing to the present.
• Past Perfect: had + verb for actions before another past action.
• Passive Voice: Usually incorrect as it creates awkward sentences.

13. Parallel Structure & Word Pairs

• Lists: Keep items parallel.
• Word Pairs: Must appear together and in parallel form.

14. Dangling Modifiers

• Descriptive phrases should directly precede the noun they describe.

15. Faulty Comparisons

• Compare equivalent items (people to people, things to things).
• Use "that of" or "those of" for singular/plural comparisons.

16. Questions Marks

• Used only for direct questions, not indirect questions integrated into sentences.

17. Shorter is Better

• Avoid wordiness and redundancy.
• The shortest grammatically correct option is usually preferred.

18. Adjectives vs. Adverbs (ACT Only)

• Adjectives modify nouns; Adverbs modify verbs.
• Comparatives and Superlatives: Do not double up more/-er or most/-est.

19. Pronoun Case (ACT Only)

• Plural pronouns tested with proper names (e.g., Rob and me).

20. Diction & Idioms

• Could/Should/Would/Might HAVE, not OF.
• Answer preposition-verb questions by ear.
• Register: Answers should not be too formal or informal.