Unlike the old SAT, the new SAT will assess conventions of punctuation. You will be asked to observe standard punctuation practices, including within-sentence punctuation. Within-sentence punctuation includes colons, semicolons, dashes, and parentheses. This month’s focus is on dashes and parentheses.
The rule is:
Dashes and parentheses both separate information that is less relevant than an aside (a clause that is related, but not essential, to the sentence). The separated information will be an interesting but unnecessary explanation or an interesting but unnecessary detail.
Here is an example of an aside:
These dogs, all of which are cuddly and cute, have a ferocious bark.
The phrase “all of which are cuddly and cute” is an aside; it is related to the sentence, but it is not essential to the sentence.
Here are examples of appropriate uses of dashes and parentheses:
Abraham Lincoln – the tallest president in American history – supported the ratification of the Thirteenth Amendment.
Abraham Lincoln (the tallest president in American history) supported the ratification of the Thirteenth Amendment.
The phrase “the tallest president in American history” should be separated by either dashes or parentheses; it is an interesting piece of information about Abraham Lincoln, but it is an unnecessary detail in the context of the complete sentence.
The use of either dashes or parentheses depends on your personal preference! There is no rule that states dashes should be used in certain contexts and parentheses in other contexts.
Now try this:
Where would you place the dashes or parentheses in the following sentence?
The Great Gatsby which I’ve read twice is a classic of American literature.