1. Sentence Structure
Section 7

2. Brief Review
An independent clause  contains a subject, a verb, and a complete thought.
It can stand alone as a sentence.
For example:
I wrote my first novel last year.
A dependent clause contains a subject and a verb, but no complete thought.
It cannot stand alone as a sentence.
Example:
After I wrote my first novel last year

3. Sentences
According to their structure (i.e. independent/dependent clauses), sentences may be classified as:
Simple
Compound
Complex
Compound-complex

4. Simple Sentences A SIMPLE SENTENCE has one independent clause.
That means it has no dependent clauses
It may, however, have compound elements
Examples of simple sentences:
John reads novels.
Tom enjoys newspapers.
John and Tom read comics.
Tom reads novels and newspapers.
John reads and enjoys nonfiction.
John and Tom read and enjoy novels and comics.
NOTE: NO commas separate two compound elements (subject, verb, direct object, indirect object, subjective complement, etc.) in a simple sentence.

5. Compound Sentences
A COMPOUND SENTENCE has at least two independent clauses joined by:
a comma followed by a coordinating conjunction (for, and, nor, but, or, yet, so) OR
a semicolon followed by a conjunctive adverb (e.g. however, therefore)
a semicolon alone
A compound sentence contains no dependent clauses

6. Compound Sentences Examples: Tom reads novels, but Jack reads comics.
This is an example of two independent clauses joined by a comma and a coordinating conjunction
Tom reads novels; however, Jack reads comics.
This is an example of two independent clauses joined by a semicolon and a conjunctive adverb
Tom reads novels; his friend reads comics.
This is an example of two independent clauses joined by a semicolon alone
NOTE: In all the examples, there is a subject and verb on each side of the punctuation

7. Complex Sentences
A COMPLEX SENTENCE has only one independent clause joined to at least one dependent clause
The dependent clauses are always headed by a subordinating conjunction or a relative pronoun (sometimes understood) that join them to the independent clause
Ex: who, whom, whose, which, that, what, after, although, as, as if, because, since, when, whenever, where, wherever, whether, while, etc.

8. Complex Sentences Examples:
Although Tom reads novels, Jack reads comics.
Here you have: Dependent clause, independent clause.
Jack reads comics although Tom reads novels.
In this example, you have: Independent clause dependent clause.
Jack Smith, who reads comics, rarely reads novels.
Here you have: Independent, nonessential dependent clause, clause.
People who read comics rarely read novels.
And lastly: Independent essential dependent clause clause.

9. Compound-Complex Sentences
A COMPOUND-COMPLEX SENTENCE has at least two independent clauses joined to one or more dependent clauses
This type of sentence is a simple combination of the compound sentence and the complex sentence
To figure out if you have a compound-complex sentence simply count the number of independent and dependent clauses
2+independent clauses and 1+dependent clause(s)=compound-complex

10. Compound-Complex Sentences
Examples:
While Tom reads novels, Jack reads comics, but Sam reads only magazines.
Here you have: Dependent clause, independent clause, coordinating conjunction independent clause.
Tom reads novels, but Jack reads comics because books are too difficult.
This has: Independent clause, coordinating conjunction independent clause dependent clause.
Jack, who reads comics, rarely reads novels; however, Tom enjoys novels.
This one has: Independent, dependent clause, clause; conjunctive adverb, independent clause.
People who read comics rarely read novels; they often find books difficult.
And, lastly: Independent dependent clause clause; independent clause.