1. Understanding the Sentence Unit
Compound and Complex Sentences
Mr. Ronzoni
Little Flower Catholic High School for Girls
2012

2. Compound Sentences
A compound sentence consists of two or more independent clauses. (An independent clause has a subject and a verb, and it makes sense when standing by itself.)
The clauses may be joined by a coordinating conjunction or by a semicolon. Also, use a comma before each of the coordinating conjunctions.

3. Compound Sentences
You can remember the coordinating conjunctions by the acronym
FANBOYS;
(for – and- nor – but – or – yet – so - ; ).
Simple rule: Look for two complete sentences connected by one of the coordinating conjunctions or by a semicolon. Also, the coordinating conjunction is preceded by a comma.

4. Compound Sentences Here is an example of a compound sentence:
Joey lost a fortune in the stock market, but he still seems able to live quite comfortably.
Here is the test for a compound sentence:
1. The sentence is compound because each clause is independent, and each can be a separate sentence:
Joey lost a fortune in the stock market.
He still seems able to live quite comfortably.
2. The clauses are connected by the FANBOYS; word but.

5. Compound Sentences vs. Compound Verbs
A compound sentence (CS) has two subjects and two verbs. A sentence that has a compound verb (CV) has one subject and two verbs; it is a simple sentence.
Here is a compound sentence:
subject verb subject
CS Marcie went to Barnes & Noble, and she
verb
bought a book.

6. Compound Sentences vs. Compound Verbs
Here is a simple sentence with a compound verb. It has one subject and two verbs.
subject verb verb
CV Marcie went to Barnes & Noble and bought a book.
Simple rule: Look for the coordinating conjunction. If it is not preceded by a comma, and if there is only one subject with two verbs, it is a simple sentence with a compound verb.

7. Complex Sentences
A complex sentence consists of an independent clause and a dependent clause. (A dependent clause has a subject and a verb, and it is preceded by a subordinating conjunction.)
A dependent clause can never stand by itself, even though it has a subject and a verb. An independent clause may precede or follow a dependent clause.

8. Complex Sentences
Here is a list of the most common subordinating conjucntions:
after if though
although if only till
as in order that unless
as if now that until
as long as once when
as though rather than whenever
because since where
before so that whereas
even if than wherever
even though that while

9. Complex Sentences Here are some examples of complex sentences:
dependent clause independent clause
Although it is raining, I prefer not to carry an umbrella.
independent clause dependent clause
I prefer not to carry an umbrella although it is raining
Notice that a comma is used to separate the two clauses in a complex sentence only when the sentence begins with a dependent clause.

10. Complex Sentences
Remember that a dependent clause can never stand by itself, even though it has a subject and a verb. Look at these examples of dependent clauses. Each one is a fragment:
When I am tired from a long day at school.
Because I missed the bus.
Whenever I get bored during summer vacation.
Each dependent clause must be joined to an independent clause. These are complete sentences:
When I am tired from a long day at school, I take a nap on the sofa.
I arrived late for school because I missed the bus.
Whenever I get bored during summer vacation, I read a book.