Punctuation
Master the rules for periods, semicolons, colons, dashes, and coordinating conjunctions.
1Periods and Semicolons
Rule:
On the SAT and ACT, periods and semicolons are used interchangeably to separate two complete sentences.
Key Points:
- Both periods and semicolons can separate two independent clauses
- Semicolons can precede conjunctive adverbs (however, therefore, etc.)
- Never use a semicolon before a coordinating conjunction (FANBOYS)
Correct: The experiment was successful. The results were published.
Incorrect: The experiment was successful, the results were published. (comma splice)
Practice Questions
2Colons and Dashes
Rule:
Colons and dashes introduce lists and explanations. They must follow a complete sentence.
Key Points:
- Must follow a complete independent clause
- Can be followed by a list, explanation, or another complete sentence
- Never use after a verb or preposition directly
Correct: She had one goal—to win the championship.
Incorrect: She bought: apples, bananas, and oranges.
Practice Questions
3FANBOYS (Coordinating Conjunctions)
Rule:
FANBOYS (For, And, Nor, But, Or, Yet, So) are coordinating conjunctions that join two independent clauses with a comma.
Key Points:
- Use a comma before FANBOYS when joining two independent clauses
- No comma needed when the second clause doesn't have a subject
- FANBOYS = For, And, Nor, But, Or, Yet, So
Correct: He wanted to go to college and pursue a degree. (no comma - implied subject)
Incorrect: She studied all night, she still felt unprepared. (comma splice)
Practice Questions
Commas
Learn proper comma usage with dependent clauses, transitions, and essential/non-essential information.
4Dependent Clauses
Rule:
When a dependent clause comes before an independent clause, use a comma. When it comes after, usually no comma is needed.
Key Points:
- Dependent clause first = comma after it
- Independent clause first = usually no comma
- Common dependent clause starters: when, because, although, if, since
Correct: The students will leave when the bell rings.
Incorrect: When the bell rings the students will leave. (missing comma)
Practice Questions
5Transitions (Conjunctive Adverbs)
Rule:
Transitions like however, therefore, furthermore connect ideas and require specific punctuation.
Key Points:
- Use semicolon before and comma after when connecting sentences
- Common transitions: however, therefore, furthermore, nevertheless, consequently
- Choose transitions that match the logical relationship
Correct: The roads were icy; therefore, many accidents occurred.
Incorrect: The experiment failed, however, we learned valuable information.
Practice Questions
6Non-Essential Information
Rule:
Non-essential information should be set off with matching punctuation: commas, dashes, or parentheses.
Key Points:
- Use two commas, two dashes, or two parentheses
- Never mix different types of punctuation
- The sentence should make sense without the non-essential information
Correct: My brother—who lives abroad—is visiting.
Incorrect: My brother, who lives abroad—is visiting. (mixed punctuation)
Practice Questions
7Essential vs. Non-Essential
Rule:
Essential information identifies which specific thing you're talking about. Non-essential information provides extra details.
Key Points:
- Essential information: no commas
- Non-essential information: use commas, dashes, or parentheses
- Ask: "Do I need this information to identify what I'm talking about?"
Non-essential: My sister, who is a doctor, lives in Boston. (extra information)
Context matters: The author Stephen King wrote many novels. (if context is clear)
Practice Questions
8Comma Rules
Rule:
Commas separate items in lists, coordinate adjectives, and set off introductory elements.
Key Points:
- Use commas to separate items in a series
- Use commas between coordinate adjectives
- Never separate subject and verb with a comma
- Use commas after introductory elements
Correct: The tall, dark stranger entered the room.
Incorrect: The cat, jumped over the fence. (separates subject and verb)
Practice Questions
Apostrophes
Understand possessive forms and contractions to avoid common errors.
9Apostrophes
Rule:
Apostrophes show possession and form contractions. Know the difference between its/it's, whose/who's, etc.
Key Points:
- Possessive: add 's to singular nouns, ' to plural nouns ending in s
- Contractions: it's = it is, who's = who is, they're = they are
- Possessive pronouns (its, whose, theirs) don't use apostrophes
Correct: The children's toys were everywhere. (irregular plural)
Incorrect: The dog wagged it's tail. (it's = it is)
Practice Questions
Pronouns
Master pronoun agreement and subject-verb agreement rules.
10Pronoun Agreement
Rule:
Pronouns must agree with their antecedents in number and gender. Use who/whom correctly.
Key Points:
- Singular antecedents take singular pronouns
- Use "who" for subjects, "whom" for objects
- Use "which" for things, "who" for people
- Collective nouns are usually singular
Correct: To whom did you give the assignment?
Incorrect: Each student must bring their own lunch. (number disagreement)
Practice Questions
11Subject-Verb Agreement
Rule:
Subjects and verbs must agree in number. Ignore prepositional phrases and focus on the true subject.
Key Points:
- Singular subjects take singular verbs
- Ignore prepositional phrases when finding the subject
- Collective nouns are usually singular
- With "neither...nor," verb agrees with the closer subject
Correct: Neither the teacher nor the students were ready.
Incorrect: The group of students are studying. (group is singular)
Practice Questions
Verbs & Sentence Structure
Learn about verb tenses, parallel structure, modifiers, and adjective/adverb usage.
12Parallel Structure
Rule:
Items in a series should be in the same grammatical form (all nouns, all verbs, all phrases, etc.).
Key Points:
- Keep the same grammatical form in lists
- All gerunds, all infinitives, or all base verbs
- All nouns, all adjectives, or all phrases
- Maintain consistency throughout the series
Correct: She is intelligent, creative, and hardworking. (all adjectives)
Incorrect: She likes swimming, running, and to bike. (mixed forms)
Practice Questions
13Dangling Modifiers
Rule:
Modifying phrases must clearly refer to the subject that immediately follows them.
Key Points:
- The subject after the comma must be doing the action in the modifier
- Common problem: modifier seems to refer to the wrong noun
- Fix by making the correct subject follow the modifier
Correct: After I studied all night, the exam was easy.
Incorrect: Walking to school, the rain started falling. (rain wasn't walking)
Practice Questions
14Idioms
Rule:
Certain words require specific prepositions. These combinations must be memorized.
Key Points:
- Good at, responsible for, different from, capable of
- Talent for, interested in, worried about
- These combinations are fixed and must be memorized
- Context doesn't change the required preposition
Correct: He is responsible for the project.
Incorrect: She is good in mathematics. (wrong preposition)
Practice Questions
15Verb Tenses
Rule:
Maintain consistent verb tenses and use the correct tense to show the relationship between actions.
Key Points:
- Keep tenses consistent within a sentence
- Use past perfect for actions completed before other past actions
- Use "would" instead of "will" in reported speech with past tense
- Present perfect connects past to present
Correct: When I arrived, she had already left. (past perfect)
Incorrect: She walked to the store and buys groceries. (mixed tenses)
Practice Questions
16Adjectives vs. Adverbs
Rule:
Use adjectives to modify nouns and after linking verbs. Use adverbs to modify verbs, adjectives, and other adverbs.
Key Points:
- Adjectives modify nouns and follow linking verbs
- Adverbs modify verbs, adjectives, and other adverbs
- Linking verbs: be, seem, appear, taste, feel, sound, look
- Good/well, bad/badly are commonly confused
Correct: The food tastes good. (adjective after linking verb)
Incorrect: She sings beautiful. (adjective can't modify verb)