Grammer - SAT

Periods & Semicolons: Key Points

Equivalence:

  • Semicolon = Period

  • On the SAT and ACT, they are considered identical; you won't choose between them.

Usage:

  1. Between Two Complete Sentences:

    • Example (Period): London is an old city. It has been inhabited for around 2,000 years.

    • Example (Semicolon): London is an old city; it has many new buildings.

  2. Before Conjunctive Adverbs (e.g., however, therefore, moreover):

    • Example: London is an old city; however, it has many new buildings.

    • Example: London is an old city; therefore, it has buildings from many different eras.

Important Tips:

  • Always read through to the period to identify complete sentences.

  • Watch for sentence boundary issues where one sentence blends into the next.

Example of Incorrect and Correct Sentence Boundaries:

  • Incorrect: Barbara McClintock is a scientist whose discovery of “jumping” genes helped earn her the Nobel Prize in 1983, she won the award in Physiology or Medicine.

  • Correct: Barbara McClintock is a scientist whose discovery of “jumping” genes helped earn her the Nobel Prize. In 1983, she won the award in Physiology or Medicine.




Colons and Dashes: Key Points

Equivalence:

  • Colons and single dashes are grammatically identical on the SAT and ACT.

  • Used to introduce lists and explanations.

  • Colons are tested more frequently.

Usage:

  1. Following a Complete Sentence:

    • Must follow a full sentence that makes sense on its own, but can have a fragment or full sentence come after it

    • Example (Correct): They made an important discovery: a new species.

    • Example (Incorrect): They made: a new species.

  2. Before a List:

    • Incorrect: London is home to a variety of: museums, castles, and shops.

      • Reason: Incomplete sentence before colon

    • Incorrect: London is home to a variety of attractions including: museums, castles, and shops.

      • Reason: Incomplete sentence before colon

    • Correct: Visitors to London often visit three types of attractions: museums, castles, and shops.

    • Correct: Visitors to London often visit three types of attractions—museums, castles, and shops.

  3. Before an Explanation:

    • Correct: The Great Wall lost its purpose: the Chinese empire extended beyond it.

    • Correct: The Great Wall lost its purpose—the Chinese empire extended beyond it.

Important Notes:

  • When a colon or dash separates two COMPLETE sentences, it acts like a period or semicolon.

  • On digital SAT questions, correct answers often involve colons when asking you to separate two COMPLETE sentences, not one complete sentence followed by a fragment

Comma + FANBOYS: Key Points

Equivalence:

  • Comma + FANBOYS = Period = Semicolon

  • FANBOYS: For, And, Nor, But, Or, Yet, So

Usage:

  1. Joining Two Independent Clauses:

    • Example (Correct): London is a very old city, but some parts of it are extremely modern.

    • Example (Correct): London is a very old city, and it is very appealing to tourists.

  2. Comma Splices:

    • Incorrect: Two sentences joined by a comma without a FANBOYS conjunction.

      • Example (Incorrect): London is a very old city, it has some extremely modern parts.

        • Correct: London is a very old city. It has some extremely modern parts.

        • Correct: London is a very old city; it has some extremely modern parts.

      • Example (Incorrect): London and Paris are two of the world’s most popular cities, they are visited by millions of tourists every year.

        • Correct: London and Paris are two of the world’s most popular cities. They are visited by millions of tourists every year.

        • Correct: London and Paris are two of the world’s most popular cities; they are visited by millions of tourists every year.

  3. Comma + FANBOYS + Verb (No Subject) = WRONG:

    • When two clauses share the same subject, and the subject does not appear in the second clause, do not use a comma before the FANBOYS conjunction.

    • Incorrect: London is a very old city, but has many modern buildings.

      • Reason: There is no subject in the second clause.

      • Plug in: London is a very old city. Has many modern buildings. (Doesn't make sense)

    • Correct: London is a very old city but has many modern buildings.

Quick Reference:

  • Comma + FANBOYS = Period = Semicolon

    • Correct: London is a very old city, but some parts of it are extremely modern.

    • Correct: London is a very old city, and it is very appealing to tourists.

  • Avoid Comma Splices:

    • Incorrect: London is a very old city, it has some extremely modern parts.

    • Correct: London is a very old city. It has some extremely modern parts.

    • Correct: London is a very old city; it has some extremely modern parts.

  • No Comma if Same Subject in Both Clauses:

    • Incorrect: London is a very old city, but has many modern buildings.

    • Correct: London is a very old city but has many modern buildings.


Commas & Dependent Clauses: Key Points

Definition:

  • Dependent clauses (fragments) cannot stand alone as complete sentences.

  • They start with subordinating conjunctions like although, because, when, until, while, since, before, and after.

Examples of Dependent Clauses:

  • Because the plant requires sunlight

  • When the exhibit opened

  • After the book was published

Rules for Combining Clauses:

  1. Dependent Clause First:

    • Must be followed by a comma.

    • Incorrect: Because London is a very old city it has buildings from many different eras.

    • Correct: Because London is a very old city, it has buildings from many different eras.

    • Incorrect: Although London is a very old city it has many modern buildings.

    • Correct: Although London is a very old city, it has many modern buildings.

  2. Independent Clause First:

    • No comma needed before the dependent clause.

    • Correct: London has buildings from many different eras because it is a very old city.

    • Correct: London has many modern buildings although it is a very old city.

Quick Reference:

When Dependent Clause Comes First:

  • Rule: Use a comma after the dependent clause.

    • Correct: Because London is a very old city, it has buildings from many different eras.

    • Correct: Although London is a very old city, it has many modern buildings.

When Independent Clause Comes First:

  • Rule: No comma needed before the dependent clause.

    • Correct: London has buildings from many different eras because it is a very old city.

    • Correct: London has many modern buildings although it is a very old city.

By following these guidelines, you can correctly use commas with dependent and independent clauses in your writing.



Non-Essential Information: Key Points

Non-essential information (clause, phrase, or word) can be removed from a sentence without affecting its essential meaning. It acts as an interruption, and when removed, the sentence should still make sense.

Punctuation for Non-Essential Information:

  1. Two Commas

  2. Two Dashes

  3. Two Parentheses

Note: Only one type of punctuation can be used at a time. Mixing punctuation types is incorrect.

Rules for Non-Essential Information

A. Two Commas:

  • Most common punctuation for non-essential clauses.

  • One comma at the beginning and one at the end.

  • Correct: London, which is a very old city, has some extremely modern parts.

    • London … has some extremely modern parts.

Common Errors:

  • Incorrect: London which is a very old city, has some extremely modern parts.

  • Incorrect: London, which is a very old city has some extremely modern parts.

  • Incorrect: London—which is a very old city, has some extremely modern parts.

Single Words (e.g., however, though):

  • Correct: London is a very old city. It does, however, have some modern parts.

  • Incorrect: London is a very old city. It does, however have some modern parts.

  • Incorrect: London is a very old city. It does however, have some modern parts.

B. Two Dashes:

  • Identical to commas for non-essential information.

  • Correct: London—which is a very old city—has some modern parts.

Exception: Single Words: ONLY USE COMMAS

  • Incorrect: London is a very old city. It does—however—have some modern parts.

  • Correct: London is a very old city. It does, however, have some modern parts.

C. Two Parentheses:

  • Used to indicate non-essential information.

  • Correct: London (which is a very old city) has some modern parts.

Common Errors with Parentheses:

  • Comma before an open parenthesis is incorrect.

    • Incorrect: London, (which is a very old city) has some modern parts.

  • Comma after a close parenthesis is usually incorrect.

    • Incorrect: London (which is a very old city), has some modern parts.

Rare Exception:

  • A comma may be required after a close parenthesis for an unrelated reason (like FANBOYS conjunction to connect to independent clauses)

    • Correct: London has been inhabited continuously since Roman times (47 A.D., to be exact), but it has some very modern parts.

Position of Non-Essential Information

At the Beginning (only use one instead of two):

  • Commas:

    • Correct: However, London has some modern parts.

  • Dashes:

    • Correct: However—despite its age—London has some modern parts.

  • Parentheses:

    • Correct: However (despite its age), London has some modern parts.

At the End (only use one instead of two):

  • Commas:

    • Correct: London has some modern parts, however.

  • Dashes:

    • Correct: London has some modern parts—even though it is very old.

  • Parentheses:

    • Correct: London has some modern parts (even though it is very old).