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The Least You Should Know about

Punctuation and Sentence Mechanics

   Commas       Major Sentence Errors (comma splices, fused sentences, fragments)      Basic Rules of Punctuation: Commas, Semi-colons, Colons      Apostrophes            Sentence Types             Pronoun Basics

The Least You Should Know about Commas

Where should you place a comma?

1. Place a comma after introductory material (to mark the spot where the introductory material ends and the main thought begins).

--On an average morning, I wake up around 5 a.m.

--If I have studied until after midnight, I wake up around 6 a.m.

--However, I need seven hours of sleep to avoid being very grumpy all day.

            2.  Place a comma between each item in a series or list (three or more items).

--The dog was wet, muddy, and cold.

3.   Place a comma BEFORE a coordinating conjunction (FANBOYS word) IF the material on BOTH sides could stand as a separate sentence.

--The dog was wet and muddy, but she was very happy to be home.

--The dog was wet and muddy, and her fur was full of burrs.

4.  Place a set of commas, one at the beginning and one at the end, around material that interrupts material that could stand as a separate sentence.

--interjections Proper lighting, according to my eye doctor, is essential to avoid eye strain.

--appositives: My eye specialist, Dr. Jones, also sells expensive lighting systems.

--non-restrictive clauses: Eye strain, which affects many people, often reduces reading ability.

5.   Place a comma before an interjection, appositive or non-restrictive clause that ends a sentence.

--Proper light is essential to avoid eye strain, according to my eye doctor.

            6.  Place a comma between two or more adjective or adverbs that independently modify a noun or verb.

He was wearing a light, blue shirt (= a blue shirt which is lightweight). [[Compare: He was wearing a light blue shirt = a shirt that is light blue in color.]]

            7. Use a comma to separate the items in dates and addresses.

--On May 12, 1997, I sent a letter to 123 Elm St., Seattle, WA.

      8.  Use a comma to set off direct speech and direct quotations from the "tag" line.

--According to Dr. Smith, "this play is one of Shakespeare’s best" (37).

Where should you never place a comma?

After a word or phrase that begins the sentence but is an essential part of the clause: most common errors occur with subordinating conjunctions such as "although" and "because."

--Although the dog was wet and muddy, she was happy to be home. (Note: the comma follows the whole introductory clause, not the first word.)

Before a coordinating conjunction (FANBOYS word) joining any two things other than independent clauses (material that could stand alone as a sentence).

--The wet dog was muddy and covered from head to toe with burrs.

Before and after a restrictive clause (a clause that establish which one of more than one possibility is the one you mean). (Compare item 4C above--non-restrictive clauses.)

--The boy who had just hit the baseball through the window immediately confessed in order to protect the boy who was being accused.

Before a verb, unless the comma is the second one in a set of two and is marking one of the three kinds of interruptions (interjections, appositives, non-restrictive clauses).

--Swimming across the English Channel was a popular feat a few years ago. (Note: no comma before "was"). [[compare: Swimming, which is an aerobic exercise, was discouraged for ladies in the nineteenth century.]]

Any place not indicated above in the list of eight places where you should place a comma.

The Least You Should Know about Major Sentence Errors

What are Major Sentence Errors?

Any error that indicates a confusion about the nature of and requirements for marking the beginnings and endings of a complete thought (a potential sentence unit) is a major sentence error.

The most common major sentence errors are fragments (marking something as a sentence—a complete thought--when it isn’t) and fused sentences (running two complete thoughts together in such a way as to suggest only one complete thought).

Fragments come in two main forms:

1. Units of thought which are missing one or both of a complete subject or a complete verb or have a problem matching a potential subject with a potential verb;

--example: In the very early morning, bats and other flying creatures circling their homes.

--example: The cat, which is a very independent animal.

2.  Units of thought which would be complete sentences except that they begin with a word identifying them as a less important idea, designed to be connected to a complete thought.

--example: Although the cat is a very independent animal. [[The material would be a complete thought except for the word "although" which says that the material must be attached to another thought, which could stand by itself.]]

--example: When bats circle their homes in the very early morning. [[The material would be a complete thought except for the word "when" which says that the material must be attached to another thought, which could stand by itself.]]

Fused sentences come in two forms: run-ons and comma splices.

A run-on occurs when you use no punctuation where you could have used a period;

a comma splice occurs when you use a comma where you could have used a period.

--example of a run-on: The cat is a very independent animal a dog, on the other hand, wants to please humans. [The sentence" runs-on "between "animal" and "a".]]

--example of a comma splice: The cat is a very independent animal, a dog, on the other hand wants to please humans. [[The comma splice occurs between "animal" and "a".]]

How to Fix Fragments:

In most cases, a fragment occurs as an afterthought following a complete sentence. In such a case, attach the fragment to the sentence that precedes it.

--example: A cat can be very affectionate. Although it is an independent animal. =A cat can be very affectionate although it is an independent animal.

In some cases, the writer has left out some part of the sentence that needs to be expressed directly.

--example:  Although I believe the book has been stolen. = Although I believe the book has been stolen, I could be mistaken.

--example:  The dog running down the street. = The dog was running down the street. 

Basic Rules of Punctuation: Commas, Semi-colons & Colons

Commas:

The "put a comma in when you pause" rule you learned in elementary school was for elementary school. For more complex writing, the "pause rule" is useful ONLY to indicate that you MAY need some sort of punctuation. The college level rule is "consider putting in some sort of punctuation when you pause."

If in doubt, leave it out. If a comma is genuinely the mark of punctuation you MAY need, remember that there are many stylistic reasons for breaking a "rule" that says a comma is necessary; there are few reasons for adding a comma that is not technically required. The odds favor leaving out an iffy comma.

Commas separate: they separate items in a list (usually); they separate adjectives in a series; they separate an independent clause from another independent clause joined by a coordinating conjunction; they separate almost anything introductory from the main part of the clause; they separate (in a set of two) an "extra" bit of information from the main part of the clause.

Commas DO NOT SEPARATE the subject from the verb or the verb from the object.

SEMI-COLONS:

A semi-colon is NOT a stronger comma (usually); it is a weaker period. With a very few exceptions, if you could not use a period, you cannot use a semi-colon.

A semi-colon shows balance, symmetry, opposition, or contrast between two clauses each of which could stand (grammatically speaking) as a separate sentence.

A semi-colon is often used with connectives that are not strong enough to join independent clauses (words such as "however," "therefore," or "consequently" —conjunctive adverbs). Note that most of these weak connectives can appear somewhere other than at the beginning of a second independent clause: the semi-colon goes between the independent clauses, regardless of where the conjunctive adverb appears.

COLONS:

In most types of writing (other than for headings), a colon can only be used after an independent clause. Unlike the semi-colon, the colon does not need an independent clause following it.

Colon error:  The three main types of literature are: drama, poetry, and prose fiction.

Correct use of the colon: Literature has three main types: drama, poetry, and prose fiction.

The colon shows that the following material explains, expands, completes, or defines the preceding material. The most common sorts of explanations, expansions, etc. are lists and direct quotations. Note, however, that you do not automatically use a colon with a list or a direct quote.

Colon error:  Shakespeare says: "To be or not to be/ That is the question."

Correct use of the colon:  One of Shakespeare's most famous lines is from Hamlet's famous contemplation of suicide: "To be or not to be/ That is the question."

Pity the Poor, Overworked Apostrophe

1. they show where the missing letter goes in contractions and

2 they show possession (ownership) for NOUNS.

Apostrophes are not used to show possession for pronouns—the form of the word changes to show possession for pronouns (he Þ his ; they Þ their ; it Þ its )

Apostrophes are not used to show plurals (although a plural noun can be possessive as well as plural).

Apostrophes with Contractions:

In informal writing, use an apostrophe with words we typically run together in speech: it is becomes it’s; cannot becomes can’t; do not becomes don’t and so on. Note that the apostrophe replaces the missing letter(s).

The only times you could possibly use an apostrophe with a pronoun or a verb is to show a contraction.

The following forms do not exist: its’ his’ theirs’ hers’. Any of these misuses of the apostrophe will seriously annoy a literate reader (such as the person grading your papers).

Apostrophes to show Possessive Case (ownership) for NOUNS

Nouns and pronouns change their form, usually through the addition of a new ending, to show their function and/or their meaning in the sentence:

to make dog plural, add s = dogs; to make child plural add ren = children.

to make the word [ dog ] possessive, add ‘s = dog’s ;

to make the word [ dogs ] possessive add the apostrophe = dogs’

Example: A dog’s bone is a prized possession. Sometimes, two dogs will share a bone. These two dogs’ bone (one bone belonging to two dogs) will not last very long.

if the noun you start with ends in s, just add the apostrophe.

The book belonging to the child = the child’s book

The book belonging to the children = the children’s book.

Most nouns become plural by adding s, so for most nouns, the possessive singular (one noun owning/possessing something) is formed by adding ‘s ; the possessive plural (more than one noun owning/possessing something), which already ends in s, is formed by adding just the apostrophe.

The bone belonging to the dog = the dog’s bone

The bone belonging to the dogs = the dogs’ bone

Compare the simple plural: Two dogs were running down the street.

Note: a possessive noun is followed by another noun: Tom’s book; the child’s candy; Ralph’s favorite charity; Martha’s Vineyard; Siskel’s movie of the week.

Sentence Types

Sentences come in four types: simple, compound, complex, and compound-complex. Sophisticated writing has a high percentage of complex and compound-complex sentences.

Sentence types depend on the number and types of clauses.

Words most often function in units, either phrases or clauses. A clause is a unit that contains a subject and a matching complete verb. A phrase is any other type of unit.

Clauses come in two types: independent (main) and dependent (subordinate). An independent clause is any clause that can stand by itself; a dependent clause has exactly the same features as an independent clause except that it starts with a subordinating conjunction—a word that says the clause is intended to support an independent clause.

The most common subordinating conjunctions (dependent words) are although though because since if when and after. (Note: none of these words is immediately followed by a comma). See your text for a more complete list of common subordinating conjunctions.

Relative conjunctions (who, whom, that, which) are also subordinating conjunctions.

Note: however, nevertheless, therefore, also, and in fact are not subordinating conjunctions. (Note: all of these words are immediately followed by a comma).

Simple sentences:

A simple sentence has only one clause. A simple sentence can be as short as one subject and one verb: Birds fly.

A simple sentence can have a compound subject (more than one thing doing the action) and/or a compound verb (more than one action), provided both/all subjects function as a unit performing both/actions: Birds and insects fly. Birds fly and eat insects. Birds and bees love flowers and fly near them whenever possible.

A simple sentence can have any number of modifying words and phrases.

On bright, sunny mornings, small birds and buzzing bees dearly love fragrant and brightly colored flowers.

Compound sentences:

A compound sentence has two independent clauses, joined by a coordinating conjunction (for and nor but or yet so) or by a semi-colon or by a colon. Birds can fly, but cats can jump.

Either clause can have compound subject, compound verb, modifying words, and/or phrases.

Complex sentences:

A complex sentence has one independent clause and at least one dependent clause.

Because birds can fly, smart birds can stay out of the reach of cats.

Smart birds can stay out of the reach of cats although very few birds are smart.

(Compare this compound sentence: Smart birds can stay out of the reach of cats; however, very few birds are smart.)

Either clause can have compound subject, compound verb, modifying words, and/or phrases.

Compound-complex sentences:

A compound-complex sentence has at least two independent clauses, joined by a coordinating conjunction, a semi-colon, or a colon AND a dependent clause.

Because of the nature of hunted and hunter, birds try to stay away from cats, and even well-fed cats will try to catch birds.

Pronoun Basics

WHICH WORDS ARE PRONOUNS?

WHAT SORT OF ERRORS OCCUR IN USING PRONOUNS?

1. The pronoun might not refer to any expressed word: pronoun reference error.

Example: Tim wrote to his aunt, and decided to enclose a picture with it. ("it" refers to an implied word, but does not refer to any expressed word.)

How to fix it: add a specific word for the pronoun to refer to, or replace the pronoun with the specific word: Tim wrote to his aunt, and decided to enclose a picture in the envelope.

2. The pronoun might logically refer to more than one word: pronoun reference error.

Example: Tom told Jerry it was his turn to do the dishes. "his" could refer to either "Tom" or "Jerry".

How to fix it: replace the pronoun with the word or words it is supposed to refer to:

Tom told Jerry it was Jerry’s turn to do the dishes.

3. The pronoun might not "agree" in number with the word it refers to (the pronoun might be plural while the word it refers to is singular): pronoun agreement error

Example: A student often has to study for long hours to pass their tests. "their" is plural and it refers to "a student"—singular.

How to fix it: usually, make the word the pronoun refers to plural: Students often have to study for long hours to pass their tests. (if the antecedent—the word the pronoun is supposed to refer to--must remain singular, replace the plural pronoun with a singular pronoun or with pronouns that do not create a gender reference error (see item #4).

          4. The pronoun might not "agree" in gender with the word it refers to (the pronoun might be masculine while the word it refers to is feminine; or the pronoun might be masculine while the word it refers to is logically neither masculine or feminine): pronoun agreement error

Example: Any doctor worth his pay will let a patient to get a second opinion on her major surgery.

How to fix it: Usually, make both antecedent and pronoun plural, to avoid the gender agreement issue, or omit the pronoun. Alternatively, make the pronoun agree with the word it refers to: Doctors worth their pay will let a patient get a second opinion on major surgery.

5. The pronoun might not be in the correct "case" (the pronoun might be in subject form while functioning as an object in the sentence): pronoun case error

Example: Give the books to Martha and I (this equals Give the books to Martha and give the books to I)

How to fix it: change the case of the pronoun to fit its function in the sentence. Give the books to Martha and me.

This page was late updated on 09/28/08