They are missing either a subject or a verb, or both.
- fluffy blankets
- has been laughing
- under the sink
- rather quickly
Dependent clauses have a subject and a verb, but they cannot stand on their own. In order to create a complete sentence or thought, they must be attached to an independent clause.
- when children laugh
- after the dance was over
- as soon as we know who won
- because there are vending machines in the halls
An Independent Clause can stand on its own, and can be used as a complete sentence.
- independent people support themselves
- children usually are not independent
- adults take care of children