Diagramming Sentences

Diagramming Overview

Remember, a sentence consists of a subject and a verb, working together to express a complete thought. Consider this sentence:

I laughed.

It has a subject, I, and a verb, laughed, and expresses a complete (if somewhat boring) thought, so it counts as a sentence, even though it's very, very short. Here's how we'd diagram it:

We jazz up boring sentences by adding more details. Those details often come in the form of modifiers (usually adjectives and adverbs). For example, by adding the adverb "loudly," I can tell my reader more about the way I laughed. Modifiers go below the main baseline like this:

We can also use prepositional phrases, clauses, and other sentence structures to add interest and detail to our sentences. Those elements can also be diagrammed.

Here's a significantly more complicated version of the first sentence:

During the funny parts of the movie, I laughed loudly.

Adding those details to the diagram enables us to see their relationship to each other (and the jobs they're doing in the sentence) in the way they are placed:

Notice that the elements on the top line are the same in both sentences. That's because the subject and the verb stayed the same. Everything else -- you know, the details we added to make the sentence more interesting -- is working to modify the verb (or the other modifiers) in the sentence. Modifiers always go below the word they describe. The only things that go on the top line are the subject, the verb, and the subject complement (i.e., the predicate adjective, predicate nominative, or direct object) -- if there is one in the sentence.