Some students have problems with sentence fragments, which are not complete thoughts; others have problems with run-on sentences which contain complete thoughts but lack correct punctuation. Remind students to be careful when correcting a run-on sentence. Often their correction results in a comma splice problem.

Incorrect: Art critics greatly admire the works of Georgia O’Keefe her beautiful colors and biomorphic shapes endear her to many.

The student has great ideas and complete thoughts, but she has literally run them together. The reader is not asked to pause, and the sentence is awkward. In this situation, you can again read the sentence to the student to see if she can hear the problem.  Or you can ask the student to read the sentence as it is written without stopping until she reaches a punctuation mark. 

A diagram is also helpful. If you show her the structure of the sentence, she may be able to see that she needs to make some changes.

Key Idea
When reading, the voice will naturally drop indicating a pause or an ending. Students can listen for this pause to help them know when to punctuate.