Calling all diagramming experts

A reader asks:

I have a sentence that I am trying to figure out how to diagram. Yes, we still diagram sentences.

Here is the sentence:

English King John signed the Magna Carta, limiting the king’s power.

I have thought a couple of different things.Maybe this is an “elliptical” sentence where the adverb “thereby” is omitted. But “limiting the king’s power” is a participial phrase. So what does it modify? King John? Or does it modify the whole sentence, and would it then be diagrammed by itself apart from the main sentence? I am stumped.Can you help or should I post to the blog to see if anyone could help?

So, readers, can you help? I gave one answer, but I am interested to see what others say.

Please post comments below, or if you have trouble with the balky log-in, click on the e-mail link and send your comment to me. I’ll post them here.

This article was originally posted by the Raleigh News & Observer, a subsidiary of The McClatchy Co.; is posted here to provide continuity; and is copyright © 2011 The News & Observer Publishing Company, which reserves the right to remove this post.