Content writing within each sentence?

I was told about my subject and predicate writing was almost good, but the word content came up and why should I put in content writing? I am happy with the subject and predicate writing. I am still baffled with the flow of each words within a sentence. I am looking for some order within each sentence, but then there's the paragraph itself for flow from the sentences. I am aware of the words within the sentence, but again it's the flow of the words within the sentence that has me bewildered. In the Dick and Jane story it's about dick and Jane. But in that time did they have subject and predicates in all sentences? Writer One