Advanced Sentence Diagramming: Diagramming Noun Clauses

The subject of this sentence is a noun clause.

What's a Noun Clause?

Just like a noun represents a person, place, thing, or idea, a noun clause is a group of words with a subject and a verb that makes a complete thought and represents a person, place, thing, or idea. A noun clause can be used in a sentence anywhere a noun can be used: as a subject, object, or complement.

You can usually tell a noun clause from a modifying clause by taking the clause out of the sentence. If the sentence still makes sense, you've probably removed a modifying clause, a clause that adds extra information to the sentence. If the sentence no longer makes sense, you've probably removed a noun clause, which adds essential information to the sentence.

Here are some examples of noun clauses. Note that when you remove them, the sentence no longer makes sense:

• As a subject: That Stella is intelligent is obvious.
• As an object: The politician admitted he had committed a crime. 
• As a predicate nominative: Your education is what you make of it.

Diagramming Noun Clauses

Let's practice diagramming "That Stella is intelligent is obvious." This sentence contains 2 linking verbs ("is" and "is"), 2 subject complements ("intelligent" and "obvious"), and "That" as a conjunction. However, in this sentence, the "that" does not change the meaning of the sentence.

There is one main thought in this sentence: "X is obvious." X stands for the subject of the sentence, "Stella is intelligent." Because the sentence has one main thought, we will draw one main base line and fill in the main verb and the main subject complement.

There is one main thought in this sentence. The main predicate has been completed.

Because the subject of the main clause is also a complete sentence, we must give it its own base line. We will add a base line on "legs" to the subject area on the base line for the main clause.

The subject of this sentence is a noun clause, and must have its own base line.

We diagram the linking verb and subject complement the same for both clauses. The linking verb follows the subject-verb divider, which passes through the base line. The subject complement is placed on the base line following the linking verb and a backslash that does not cross the base line.

We will connect "That" to "Stella" with a dashed line like other conjunctions. "That" can appear either above or below the clause.

"That" is non-essential and can appear either above or below its clause.

Just like diagramming compound, complex, and compound-complex sentences that require multiple base lines, the key to diagramming noun clauses is also the inclusion of multiple base lines. The difference is that a noun clause must be embedded into its main clause with a "mini" base line on "legs." When the noun clause is acting as a subject, the secondary base line will appear on legs within the subject area of the main clause; a clause acting as an object will appear in the object area; and a clause that acts as a predicate nominative will appear in the predicate nominative area.

Want to read more about diagramming sentences? Try 

Diagramming Determiners
Diagramming Possessive and Plural Nouns
Diagramming Multiple Independent Clauses


Copyright Amy Lynn Hess, please contact the author for permission to republish.