1. It’s the Details That Matter
To comma, or not to comma—that is the question.

2. Charlie has become more educated than his doctors ,SO S P
COMMA RULE
When joining two independent clauses place a comma before a coordinating conjunction.
A clause is a group of words with a subject and a predicate.
FOR, AND, NOR, BUT, OR, YET, SO
Here’s an example:
S P P
Charlie has become more educated than his doctors
,SO
S P
He plans to advance their research.
Charlie has become more educated than his doctors, so he plans to advance their research.

3. Charlie always wanted intelligence ,but
COMMA RULE
When joining two independent clauses place a comma before a coordinating conjunction.
A clause is a group of words with a subject and a predicate.
FOR, AND, NOR, BUT, OR, YET, SO
Here’s another one:
S P
Charlie always wanted intelligence
,but
S P P
It is affecting his relationships.
Charlie always wanted intelligence, but it is affecting his relationships.

4. You have written nearly 20 compound sentences ,and
COMMA RULE
When joining two independent clauses place a comma before a coordinating conjunction.
A clause is a group of words with a subject and a predicate.
FOR, AND, NOR, BUT, OR, YET, SO
Here’s another one:
S P P
You have written nearly 20 compound sentences
,and
S P P
You should use them in all classes.
You have written nearly 20 compound sentences, and you should use them in all classes.
Got it?

5. COMMA RULE
When joining two independent clauses place a comma before a coordinating conjunction.

6. ONLY if you’re joining clauses.
TO BE CLEAR…
This does NOT mean that you will use a comma EVERY TIME you use a word like AND, BUT, OR, SO.
ONLY if you’re joining clauses.
S P P S P P
We are practicing compound sentences, but we will practice complex sentences next week.
Here I’m joining independent clauses.
S P P
We are practicing compound sentences and complex sentences.
Here I’m NOT joining clauses.

7. ONLY if you’re joining clauses.
TO BE CLEAR…
This does NOT mean that you will use a comma EVERY TIME you use a word like AND, BUT, OR, SO.
ONLY if you’re joining clauses.
Okay, now you decide if I need a comma or not.
S P S P P
Algernon got the same operation as Charlie and his intelligence has remained. ,
Do I need a comma here?
ANSWER: YES, THIS IS A COMPOUND SENTENCE. THE COMMA/COORDINATION CONJUNCTION JOIN THE TWO INDEPENDENT CLAUSES.

8. ONLY if you’re joining clauses.
TO BE CLEAR…
This does NOT mean that you will use a comma EVERY TIME you use a word like AND, BUT, OR, SO.
ONLY if you’re joining clauses.
Okay, now you decide if I need a comma or not.
S P P P
Charlie has done research and learned about brain structures.
Do I need a comma here?
ANSWER: NO, THIS IS NOT A COMPOUND SENTENCE. THERE IS NOT ANOTHER SUBJECT DOING AN ACTION AFTER THE CONJUNCTION “AND.” (This is a SIMPLE SENTENCE.)

9. ONLY if you’re joining clauses.
TO BE CLEAR…
This does NOT mean that you will use a comma EVERY TIME you use a word like AND, BUT, OR, SO.
ONLY if you’re joining clauses.
Okay, now you decide if I need a comma or not.
S P P P
Charlie can speak several languages and solve complex math problems.
Do I need a comma here?
ANSWER: NO, THIS IS NOT A COMPOUND SENTENCE. THERE IS NOT ANOTHER SUBJECT DOING AN ACTION AFTER THE CONJUNCTION “AND.” (This is a SIMPLE SENTENCE.)

10. ONLY if you’re joining clauses.
TO BE CLEAR…
This does NOT mean that you will use a comma EVERY TIME you use a word like AND, BUT, OR, SO.
ONLY if you’re joining clauses.
Okay, now you decide if I need a comma or not.
S P
He now understands the world and all the people around him.
Do I need a comma here?
ANSWER: NO, THIS IS NOT A COMPOUND SENTENCE. THERE IS NOT ANOTHER SUBJECT DOING AN ACTION AFTER THE CONJUNCTION “AND.” (This is a SIMPLE SENTENCE.)

11. ONLY if you’re joining clauses.
TO BE CLEAR…
This does NOT mean that you will use a comma EVERY TIME you use a word like AND, BUT, OR, SO.
ONLY if you’re joining clauses.
Okay, now you decide if I need a comma or not.
S P S P
People from work were Charlie’s friends but now he is on an island. ,
Do I need a comma here?
ANSWER: YES, THIS IS A COMPOUND SENTENCE. THE COMMA/COORDINATION CONJUNCTION JOIN THE TWO INDEPENDENT CLAUSES.

12. OKAY NOW YOU TRY IT!