What you really need is Classical Writing - Homer.
The whole aim of this program is to teach the application of grammar to model sentences for analysis, along with imitation for writing words, sentences, and paragraphs, and then the narrative exercise of the progymnasma.
This book is in the works and due out this spring -- we hope!
It coordinates explicitly with Harvey for grammar instruction.
Harvey's does offer some sentences, which can be used for diagramming. You can also take sentences from your reading, CW models, or other books. As you start out, what I would recommend would be to *simplify* the sentences you take from other sources. Drop anything from them that you don't know how to diagram yet. If you know what you're looking for, you can also select sentences carefully. If necessary, paraphrase the sentence to put it into a form that can be diagrammed easily.
Here is an example:
Now that Hector was dead, King Priam, his father, had only one thought in his mind, and that was to get his body from Achilles and bring it into the City so that it might be treated with the honor befitting the man who had been the guardian of Troy.
Whew! I picked that one at random from Colum's retelling of Homer.
Here's how you can simplify/paraphrase.
Hector was dead. King Priam wanted the body. He would bring it into the City. Hector's body deserved honor. He had been guardian of Troy.
Here it is a little less simplistically, with clauses and verbals explained, and then simplified:
Now that Hector was dead [adverbial clause], King Priam, his father [appositive], had only one thought in his mind, and [compound sentence] that was to get [compound infinitive phrase used as subject complement] his body from Achilles and bring it into the City so that [adverbial clause] it might be treated with the honor befitting [participial phrase] the man who [relative clause] had been the guardian of Troy.
Hector was dead. King Priam, his father, had only one thought in his mind. He would get the body from Achilles and bring it into the City. The body should be treated with honor. Honor befits the man who had been the guardian of Troy. (Try to diagram that last, simple relative clause.)
You can either prepare your sentences ahead of time. Or, if you know grammar well yourself, you can do it "on the fly". Lene recommends dictating a modified sentence out of the model (or whatever your source is) and then having students diagram the sentence that was dictated.
It's a good idea to invest in a more advanced diagramming book as a reference for yourself if you intend to work with real sentences. (Textbooks such as Rod and Staff will carefully tailor sentences to meet the precise requirements of the lesson at hand. The benefit is that students are not overwhelmed. The disadvantage is that students do not learn how to diagram "real sentences".) The Rod and Staff Handbook is pretty good as a diagramming reference (to go beyond Mary Daly's introduction). Also, Descriptive English Grammar by House and Harman is good. There are also a couple good online sites.
For more diagramming resources, see also
www.classicalco-op.com. Click on Classical Education or the Classical Education Wiki Project, and then on grammar.
HTH,
Tracy
