Is this a sentence fragment?
The Zion Narrows, a canyon in Utah's Zion National Park, stretching for sixteen miles and, in some areas, narrowing to just twenty feet.
yes no
A sentence is a group of words that expresses a complete thought.
The band I'm in has been rehearsing daily because we have a concert in two weeks.
A sentence fragment is a group of words that does not express a complete thought.
Rehearsing daily because we have a concert in two weeks.
This fragment is missing a subject. It doesn't tell who is rehearsing.
The band I'm in.
This fragment is missing a verb. It doesn't tell what the band I'm in is doing.
Because we have a concert in two weeks.
This fragment is missing an independent clause. It doesn't tell what happened because of the concert.
This is a sentence fragment. It does not express a complete thought.
The Zion Narrows, a canyon in Utah's Zion National Park, stretching for sixteen miles and, in some areas, narrowing to just twenty feet.
Here is one way to fix the sentence fragment:
The Zion Narrows, a canyon in Utah's Zion National Park, stretches for sixteen miles and, in some areas, narrows to just twenty feet.