Answer: Parenthetical expression
Step-by-step explanation:
Parenthetical Expressions. The final use of a comma as an interrupter is to set off parenthetical expressions. A parenthetical expression interrupts the thought flow of a sentence. These expressions are not related to the rest of the sentence and could be put in parentheses. Parenthetical expressions are set off by commas to indicate to the reader their separation from the main thought of the sentence. This list contains many common parenthetical expressions:
if you ask me as I said before of course
for example for instance you know
I believe naturally as a matter of fact
in fact in my opinion by the way
Generally, it is best for a writer to use parenthetical expressions sparingly; when they are used, they should serve to qualify the information given.
Example:
Democracy, I believe, is by far the best of all world governments.
The qualifying expression "I believe" shows the reader that the writer's statement is an opinion, not necessarily a fact.
Example:
We will, of course, pay for the damage.
The expression "of course" cues the reader that the speaker had good intentions all along and that no other thought crossed his mind.
The parenthetical expression is important, but like any other expression it should be used with discretion.