ACT Preparation / Unit 2 ACT 0108 worked example, 60 to 90 seconds
Essential or Not: Commas Around a Clause
The idea
To punctuate a clause or a name inside a sentence, work in three steps. First, mark where the information begins and ends. Second, remove it and reread: if the reader still knows which person or thing is meant, it is nonessential; if not, it is essential. Third, punctuate to match: a nonessential element gets a comma on each side, or one comma before it at the end of the sentence; an essential element gets none, and a clause of that kind opens with that, not which.
In practice
Worked example: "The trail which starts behind the school is closed for repairs." Removed, the sentence reads "The trail is closed," and the reader no longer knows which trail. The clause is essential: "The trail that starts behind the school is closed for repairs." Now "Hawk Ridge Trail which starts behind the school is closed." The name already identifies the trail, so the clause is nonessential: "Hawk Ridge Trail, which starts behind the school, is closed."
Where people slip
The same clause can be essential in one sentence and nonessential in another. What decides is whether something else in the sentence already identifies what is meant.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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