For our fourth sentence, we’ll depart from movie quotes. This sentence is close to one I found myself writing in an email, and I realized that although it was perfectly clear (and grammatical — it IS acceptable to end a sentence with a preposition in English), it would make for a more complex diagram because of understood but omitted words.
Here’s the sentence: “Her research is something I have no clue about the topic of.”

First, as always, let’s find the main clause: Her research is something. The rest is, at heart, a relative clause, giving more information about “something.” But it’s a little complicated, because the relative pronoun, “which,” is absent from the sentence. So let’s think of it as “the topic of (which) I have no clue about,” which will be diagrammed as “I have no clue about the topic of (which).”
Relative clauses connect with the nouns they modify via a dotted line, so it looks like this: