Key SAT and ACT Grammar and Punctuation Rules:
1. Periods & Semicolons
- Semicolon = Period: Used between two complete sentences.
- Correct: “London is an old city. It has been inhabited for 2,000 years.”
- Correct: “London is an old city; it has many new buildings.”
- Before Conjunctive Adverbs: Like “however,” “therefore.”
- Correct: “London is an old city; however, it has many new buildings.”
- Watch for Sentence Boundaries: Avoid “sentence boundary” errors by reading each sentence fully.
- Incorrect: “Barbara McClintock… genes, she won the award.”
- Correct: “Barbara McClintock… genes. She won the award.”
2. Colons & Dashes
- Colons & Dashes Introduce Lists/Explanations:
- Before a list: “Visitors… attractions: museums, castles, shops.”
- Before an explanation: “The Wall lost its purpose: enemies came from the sea.”
- Colons and dashes can introduce full sentences or fragments. Must follow a complete thought.
3. Comma + FANBOYS (For, And, Nor, But, Or, Yet, So)
- Comma + FANBOYS = Period = Semicolon:
- Correct: “London is old, but some parts are modern.”
- Comma Splices: Avoid joining two sentences with a comma.
- Incorrect: “London is old, it has modern parts.”
- Correct: “London is old. It has modern parts.”
- Comma + FANBOYS + Verb = WRONG:
- Incorrect: “London is old, but has many buildings.”
- Correct: “London is old but has many buildings.”
4. Commas & Dependent Clauses
- Dependent Clauses: Cannot stand alone.
- Incorrect: “Because London is old it has buildings…”
- Correct: “Because London is old, it has buildings…”
5. Transitional Words & Phrases
- Types:
- Continues: “in addition,” “moreover.”
- Cause and Effect: “therefore,” “thus.”
- Contradictory: “however,” “nevertheless.”
- Cross out the transition to find the sentence’s relationship.
6. Non-Essential Information
- Punctuation Options: Use two commas, two dashes, or two parentheses.
- Incorrect: “London, which is old has modern parts.”
- Correct: “London, which is old, has modern parts.”
7. Commas with Names & Titles
- Determine Essential vs. Non-Essential:
- No commas if essential.
- Two commas if non-essential.
8. Additional Comma Uses & Misuses
- Use commas: To separate items in a list, after introductory phrases, or between adjectives.
- Do not use commas: Before/after prepositions, between subjects and verbs, or before/after “that.”
9. Apostrophes (Plural vs. Possessive)
- Nouns:
- Singular: add ‘s (e.g., the cell’s DNA).
- Plural: add s’ (e.g., the cells’ DNA).
- Pronouns:
- It’s = It is; Its = possessive form.
10. Pronouns & Nouns
- Agreement: Singular nouns = singular pronouns, plural nouns = plural pronouns.
- Incorrect: “Frida Kahlo… It was influenced…”
- Correct: “Frida Kahlo… They were influenced…”
11. Subject-Verb Agreement
- Singular vs. Plural:
- Incorrect: “The Monarch and the Red Admiral is…”
- Correct: “The Monarch and the Red Admiral are…”
12. Verb Tense
- Consistency: Keep verb tenses consistent.
- Incorrect: “Frida Kahlo earned renown… She is influenced…”
- Correct: “Frida Kahlo earned renown… She was influenced…”
13. Parallel Structure & Word Pairs
- Lists:
- Incorrect: “Pamela Meyer has collaborated… and analyzing.”
- Correct: “Pamela Meyer has collaborated… and analyzed.”
14. Dangling Modifiers
- Correct Placement:
- Incorrect: “Born in 1907, self-portraits were…”
- Correct: “Born in 1907, Frida Kahlo was…”
15. Faulty Comparisons
- Equivalent Items:
- Incorrect: “The work of… well-known as Frank Lloyd Wright.”
- Correct: “The work of… as that of Frank Lloyd Wright.”
16. Question Marks
- Direct vs. Indirect Questions:
- Direct: “How much do babies understand?”
- Indirect: “How much babies understand.”
17. Shorter is Better (ACT & Paper-Based SAT)
- When in doubt, choose the shortest grammatically correct option.
18. Adjectives vs. Adverbs (ACT Only)
- Adjectives modify nouns; adverbs modify verbs.
19. Pronoun Case (ACT Only)
- Correct: “My mother and I attended…”
20. Diction & Idioms
- Use correct prepositions and verbs.
- Correct: “Effective at keeping…”
- Incorrect: “Effective with keeping…”