1. By Robi Bhattacharjee and Andrew Liao
Commas
By Robi Bhattacharjee and Andrew Liao

2. Brief Overview Used for series Used to form compound sentences
John, Johnny, and Jonathon went to the store.
Used to form compound sentences
I went to the store + I bought an apple + I went home = I went to the store, bought an apple, and went home.
Used for interruptions
Mr. John Jones, a chimney sweeper, got soot all over his face.

3. Using Commas in a Series
Words in a series
Used to separate independent parts of speech - like nouns, verbs, and adjectives
Ex: Bob takes karate, piano, and swimming. (nouns)
Ex: Bob tripped, fell, and cried. (verbs)
Ex: Bob is big, fat, and foolish. (adjectives)

4. Using Commas in a Series (cont.)
Phrases in a Series
Used to separate independent phrases
Ex: Bob went to the store, bought apples, talked with the manager about the poor quality of their apples, and left.
Clauses in a Series
Used to separate independent clauses
Ex: Bob danced, he sang, he fell, and he cried.
Ex: As Bob was trying to study, his dog licked him, his mother kissed him, and his brother kicked him.

5. Using Commas in Compound Sentences
Join two clauses with a comma before a conjunction
Bob offered me apples + I declined = Bob offered me apples, but I declined.
Bob decided to play baseball + Bob got out a roll of wrapping paper and a crumpled piece of paper = Bob decided to play baseball, so he got out a roll of wrapping paper and a crumpled piece of paper.

6. Using Commas to set off Interrupters
Setting off expressions
Place commas around the expression of interruption, unless it is at the beginning or end of the sentence.
Bob, my friend, says hi to all of you.
A very dangerous creature, the cobra can kill Bob in an instant.
Setting off unneeded phrases/ clauses
Place commas around an interrupting phrase/clause that does not affect the sentence’s meaning.
Bob, screaming like a maniac, fell off the cliff and died.

7. Examples Ans: John played, lost, and cried.
John gave me a present + I liked it = ?
Ans: John gave me a present, and I liked it.
John a smart boy likes to play piano.
Ans: John, a smart boy, likes to play piano.

8. Practice Problems
John an ingenious child proved Einstein’s theory at age 5.
Ans: John, an ingenious child, proved Einstein’s theory at age 5.
Bob Jr. sat in a chair chewed bubble gum and farted.
Ans: Bob Jr. sat in a chair, chewed bubble gum, and farted.
An incredible discovery penicillin saved the lives of many people.
Ans: An incredible discovery, penicillin saved the lives of many people.
Tim broke his foot + Tim cried for his mommy =
Ans: Tim broke his foot, and cried for his mommy.