A sentence fragment is exactly what it sounds like – a fragment of a sentence. Though it sounds easy to avoid, some sentence fragments are harder to spot than others.

example of a sentence fragment:

There were twenty customers who ordered eggs with their spam. Although not all customers ate them.

The second sentence is a fragment.

corrections:

1. There were twenty customers who ordered eggs with their spam. Not all customers ate them.
2. There were twenty customers who ordered eggs with their spam, although not all customers ate them.