Comma Rule 10: Commas with tag elements
A tag element is a phrase or word that is placed on the end of a sentence. They are "tagged" onto the end of the sentence.
Did you finish painting the deck, Riaz?
How com the house is burned down, Riaz?
A tag element comes right after a independent clause, if there is no independent clause, there is no need for the comma. A tag element cannot be proceeded by a verb or preposition.
Walking down the strew like a cow.
Link:
http://thecraftedword.weebly.com/comma-rule-10.html
Did you finish painting the deck, Riaz?
How com the house is burned down, Riaz?
A tag element comes right after a independent clause, if there is no independent clause, there is no need for the comma. A tag element cannot be proceeded by a verb or preposition.
Walking down the strew like a cow.
Link:
http://thecraftedword.weebly.com/comma-rule-10.html