1. Comas part 3

2. Essential elements
Essential elements can be words, phrases, or clauses
Essential elements give meaning to the sentence.
Example:
The sixth-century philosopher Boethius was arrested, tortured, and bludgeoned to death.

3. Nonessential elements
Are not essential to the meaning of the sentence
Use commas before and after nonessential elements
Example:
The average world temperature, however, has continued to rise significantly.

4. Examples
The person checking tickets at the counter asked for a form of identification.
My uncle who is eighty years old walks three miles every day.
The woman who interviewed you is my sister.

5. Participles Verbals that act as adjectives Usually end in –ing or –ed
Example:
The soiled diaper.
Smiling, she hugged the drooling dog.

6. Participles If a sentence begins with a participle, add a comma.
Example:
Shaken, the man looked at the scene of the crash.