When it requires de-emphasis,

non-essential material in a
sentence is set off by a what?

pair of parentheses or a colon

THANK YOU!!!

Here are explanations for the uses of these marks of punctuation:

Colon:
http://grammar.ccc.commnet.edu/grammar/marks/colon.htm

Parentheses:
http://grammar.ccc.commnet.edu/grammar/marks/parentheses.htm

Which do you think? Let me know, and I'll tell you if you're right!

=)

parentheses

Parentheses

You are correct! When it requires de-emphasis, non-essential material in a sentence is set off by a pair of parentheses. Parentheses are used to enclose information that is not essential to the main point, but provides additional context or clarification. They can also be used to include comments or asides within a sentence. By setting off this material with parentheses, it indicates to the reader that it is not as important as the rest of the sentence.