Study It:
We use punctuation to organize and structure sentences.

Some punctuation ends sentences.

Some punctuation organizes material within sentences.

comma semicolon


The Comma
One way that commas can organize material within a sentence is by indicating the beginning and/or ending of clauses. A clause is a group of words that has a subject and verb (a subject - verb unit).

commas and dependent clauses commas and independent clauses


Commas and Dependent Clauses
The Basic Idea
Dependent clauses are subject verb units that cannot stand on their own; they must be connected to independent clauses in a sentence.

There are three types of dependent clause:
subordinate clause relative clause noun clause
How We Do It:
Subordinate Clause

Any clause that begins with a subordinate conjunction is a subordinate clause.
A subordinate clause is a dependent clause.

Here is a list of some of the more commonly used subordinate conjunctions:


because even though whether by the time
if as after until
although in order that before as soon as
since where/wherever when/whenever whereas


Commas and Subordinate Clauses

If an independent clause precedes a subordinate clause, then there is no comma.
If a subordinate clause precedes an independent clause, then you must place a comma after the subordinate clause.


  • If I pass this exam, I'll be the happiest person in the world.
In this sentence, there are two clauses:

If I pass this exam and I'll be the happiest person in the world.

If I pass this exam is a subordinate clause because it begins with the subordinate conjunction if. Because the subordinate clause precedes the independent clause, a comma must follow the subordinate clause.
  • I'll be the happiest person in the world if I pass this exam.
In this sentence, there are still two clauses:
if I pass the exam and I'll be the happiest person in the world. However, in this sentence the independent clause precedes the dependent clause. Therefore, there is no comma.


Look at this Example
Even though Queens is not particularly large in area, in this borough you'll find a wider variety of cultures than almost anywhere else in the world.
How many clauses are in this sentence?



Write the clauses (subject-verb units).



Identify the independent clause and the subordinate clause.



Why does the sentence contain a comma?




Beware
Subordinate conjunctions are often confused with sentence adverbs, such as however, therefore, and consequently.
You should be able to distinguish between these two categories of connecting words.
How We Do It:
Relative Clause
Any clause that begins with a relative pronoun is a relative clause. A relative clause is a dependent clause. Here is a list of relative pronouns:

that when
which where
who whom
why



  • I enjoy the films that Spike Lee makes.
There are two clauses in this sentence: I enjoy the films and that Spike Lee makes. Because that Spike Lee makes begins with a relative pronoun, it is a dependent clause. I enjoy the films does not begin with a relative pronoun; it is an independent clause. We can say that the relative pronoun is the connecting point for the independent and dependent clauses.

Commas and Relative Clauses


  • If the relative clause is necessary to identify the noun, then there is no comma.
  • If the relative clause is not necessary to identify the noun, then the relative clause must be separated from the rest of the sentences with one or more commas.


  • Students who have an active student ID can get into the Museum of Modern Art for free.
    In this sentence, the relative clause who have an active student ID is necessary to identify which students can get into the Museum of Modern Art for free (not just any students - only the students who have an active student ID). Therefore, there is no comma.

    • My mother, who has an active student ID, can get into the Museum of Modern Art for free.
    In this sentence, the relative clause who has an active student ID is not necessary to identify the writer's mother. Therefore, the relative clause must be separated from the rest of the sentence by framing it with commas.


    Hint


    You can use the following test to see if the relative clause is necessary or not:
    Read the sentence without the relative clause. If the identity of the noun that the relative clause is modifying is still clear, then the clause is not necessary to identify the noun and you must use commas.  If the identity of the noun is not clear, then the clause is necessary to identify the noun and you cannot use commas with the relative clause.
    Look at this example
    Motorists that don't wear seatbelts put their lives in danger.
    Write the sentence without the relative clause.



    Is the relative clause necessary to identify the noun that the relative clause is modifying?



    Does this sentence need commas?




    How We Do It:
    Noun Clauses
    A noun clause is a dependent clause. Noun clauses always begin with a noun clause pronoun. Here is a list of the noun clause pronouns:
    that how
    which/whichever why
    who/whoever when/whenever
    whom/whomever where/wherever


    • Jake eats whatever his mother cooks for him.
    There are two clauses in this sentence: Jake eats and whatever his mother cooks for him. Whatever his mother cooks for him begins with the noun clause pronoun whatever. Therefore, whatever his mother cooks for him is a dependent clause. Jake eats does not begin with a noun clause pronoun; it is an independent clause.

    Commas and Noun Clauses


    Noun clauses never require commas.



    Beware of
    Sentence Fragments with Dependent Clauses
    Because subordinate clauses, relative clauses, and noun clauses are dependent clause, they cannot stand on their own as sentences; these kinds of clauses must be connected to an independent clause.
    • Fred was late, so he gave us a long-winded excuse.  That no one found believable.
    The second "sentence" in this example is, in fact, not a sentence. That no one found believable is a relative clause. A relative clause is a dependent clause. Therefore, That no one found believable is not a sentence because it does not contain an independent clause. To fix this, we should include the relative clause in the sentence of the noun it's modifying.

    • Fred was late, so he gave us a long-winded excuse that no one found believable.
    Look at this Example
    Why should public figures behave in an ethical manner? Because youngsters often regard them as role models.

    What is the problem with the above example?



    Write a correct version of the example in the text box.







    Commas and Independent Clauses
    The Basic Idea
    Coordinating Conjunctions
    There are seven coordinating conjunctions.


    and or but nor yet so for


    independent clause + coordinating conjunction + independent clause
    How We Do It

    Commas and Coordinating Conjunctions


  • If the sentence is long and the coordinating conjunction is connecting two independent clauses, then you should put a comma before the coordinating conjunction.
  • If the sentence is short and the coordinating conjunction is connecting two independent clauses, then the comma is optional.


    • Hamlet sings in a deep voice, and Ophelia dances beautifully.


    Look at these Examples
    I always forget a name, but I always remember a face. List the independent clauses in this sentence.


    How are these independent clauses connected?




    Beware
    A comma alone cannot connect independent clauses!
    • Working students have special difficulties in arranging their schedules, teachers should not blame these students for being late for class.


    This example is incorrect because the two independent clauses Working students have special difficulties in arranging their schedules and teachers should not blame these students for being late for class are connected with only a comma. A comma cannot connect independent clauses. To fix this problem we can use either end punctuation, a semicolon, or a coordinating conjunction.
    End Punctuation: Working students have special difficulties in arranging their schedules. Teachers should not blame these students for being late for class.

    Semicolon: Working students have special difficulties in arranging their schedules; teachers should not blame these students for being late for class.

    Coordinating Conjunction: Working students have special difficulties in arranging their schedules, so teachers should not blame these students for being late for class.





    Semicolon


    The Basic Idea
    Link two independent clauses with a semicolon only when the ideas in the two clauses are very closely related.

    independent clause + ; + independent clause
    How We Do It
    • The word "generation" means thirty years; in the microcomputer industry it can mean six months.
    There are two independent clauses in this sentence: the word generation means and in the microcomputer industry it can mean six months. These two independent clauses are connected by a semicolon.


    Look at these Examples
      A backache can feel terrible; stretching can relieve the pain.

      The flea market was cheap; they bought an oak dresser for forty dollars.

      Ivory Coast has a diverse population; over 60 languages and dialects are spoken here.
    Beware
    The word immediately following the semicolon begins with a lower case letter.

    Punctuation that ends sentences
    The Basic Idea
    End Punctuation
    We use end punctuation to mark the end of a sentence. Every sentence must contain an independent clause. There are three forms of end punctuation:
    period     . question mark   ? exclamation point   !


    How We Do It
    • Schools should not adopt dress codes students should be able to dress according to their own tastes.
    This example is incorrect because there are two independent clauses schools should not adopt dress codes and students should be able to dress according to their own tastes, and these two independent clauses are not connected in any valid way. One way to fix this problem would be to use end punctuation.
    • Schools should not adopt dress codes. Students should be able to dress according to their own tastes.
    Look at this Example
    Children don't learn violent behavior from the media most children pick up violent behavior from their parents.

    List all clauses in this sentence and identify them as independent or dependent clauses.



    What is the problem with this sentence?



    How can you fix this example?



    Using end punctuation, write the correct version in the text box below.



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