Compound sentences

What is the most frequent problem you seen amongst you students writing? Is the problem addressed at all by the teacher? How would you address the problem in your own classroom?

As an early education major, I spend a lot of time reading and writing with my first grade students. My entire practicum is based off reading language arts. The students write extremely creative stories in class but they are filled with errors. Grammatical and spelling errors are to be expected at this young age but on the other hand I think they should receive more instruction on these topics. After reading chapter ten in Calderonello's text I realized one of the biggest issues I see with my students writing is run on sentences. The students are aware that by adding the word "and" continues their thoughts and extends their sentences. But more often than not I see the children use and correctly in a sentence; connecting two nouns but then repeatedly add the word to extend their writing. I read several stories yesterday while working with the students and they all had this problem. Spelling is phonetic and by reading a story you can understand what the child is attempting to say. However I think the children truly need a lesson on sentence structure and the meaning of a compound sentence.
I was not aware of how much this topic bothered me until I began reading this chapter for class.
I realized when reading the text there were so many factors about compound sentences that even I was not aware of. I did not know there was a difference between complex and compound sentences. As a teacher I need to make it my responsibility to become as much as an expert as possible on these topics. If I am not aware of the rules for compound sentences, how will I be able to teach my students. I have not seen the teacher I work with in practicum address this issue of run on sentences. I think the students should at least be aware of a compound sentence and simple ways of avoiding run on sentences. As a teacher I would take the key concepts of what I read in chapter ten and bring it down to the first grade level. I think the author offers great examples and while explaining the essence of a compound sentence I would use these examples in my class. Calderonello explains how to correctly join two subjects and two simple sentences. I would show my children these examples. To modify it for their age I would not refer to the make up of the sentences. For instance he combines two subjects and a subject and a predicate in his examples. Children are not aware of what these words mean, so I would change the way I talk about it. Other than the specific language the text offers great teaching examples I could use and elaborate on for my lesson. Calderonello's text (especially chapter 10) would be my main reference point for ideas and examples on how to teach these first grade students the correct sentence format and structure.