The young girl brought me a very long letter from the teacher (Independent clause.)
and then she quickly disappeared. (Dependent clause.)
To identify an independent clause, ask yourself if the clause can stand on its own as a sentence. Does it form a complete thought? “The young girl brought me a very long letter from the teacher” is a completely valid sentence on its own, so it has to be the independent clause.
The dependent clause doesn’t make much sense by itself. It forms an incomplete thought. So “and then she quickly disappeared” would be your dependent clause because it ‘depends’ on your independent clause and simply adds on to what the independent clause it saying.
