An independent clause is basically a complete sentence; it can stand on its own and make sense. An independent clause consists of a subject (e.g. “the dog”) and a verb (e.g. “barked”) creating a ...

A simple sentence is built from the minimum of a subject and a main verb. It can be very short in length (but doesn't have to be): 'The angry dog barks.' It puts across one simple idea: 'Rebecca sang.