The 8 Critical Parts of a Sentence Structure and Diagramming Sentences

The parts of a sentence structure and knowing how to diagram sentences should be emphasized since, as of 2022, 54% of adults read at a 5th grade level or below. Sentence structure has four main forms: simple, complex, compound, and compound complex. A simple sentence is an independent clause that may or may not have adverbs, adjectives, or prepositional phrases with it. A complex sentence is an independent clause that has one or more dependent clauses with it. Compound sentences are two or more complete, independent clauses that work together to form the sentence. Compound complex sentences are two or more complete, independent clauses with one or more dependent clauses supporting them.

There are other parts of a sentence than just the forms. The 8 other parts of a sentence structure are:

• Subject
• Verb/Predicate
• Direct Object/Predicate nominative
• Adverbs
• Articles/Adjectives
• Indirect Objects
• Prepositional Phrases
• Conjunctions

About Diagramming Sentences

Parsing vs. Diagramming

Parsing is a method of analyzing sentences. There are different ways to do this, but most consist of identifying what part of speech each word is in the sentence and what the subject and predicate and/or verb are. Diagramming sentences involves analyzing sentences then placing them in horizontal lines, making a visual representation of the sentence. Some people combine the two, and just call it parsing or diagramming sentences.

In grammar class, I was taught to parse sentences first by labeling the part of speech above each word and then diagram the sentence using horizontal lines, so I consider them different things even though they both require sentence analysis. As such, when I say diagramming sentences, I only mean making the visual representation in the form of a diagram and will be leaving parsing out of the rest of this article.  I will be going over the most common parts of speech so you can analyze the words on your own.

Why Diagram Sentences?

There are a few reasons to diagram sentences; it:

• Helps you learn the different parts of a sentence,
• Helps in editing complicated sentences,
• Gives a visual image of language,
• Helps with learning and understanding foreign languages.

Parts of a Sentence Structure

Basics

Subject and Nouns

The first of the parts of a sentence structure is the subject. A subject is the thing that is doing the action and/or the sentence is about; it is usually a noun or pronoun. A noun is the part of speech that is a person, place, or thing, which includes physical and abstract objects. Proper nouns are names of places, people, eras of time, works of art, etc.

Pronouns are words that take the place of a noun, usually to save space since the noun is long and/or already been used many times to the point of redundancy. Pronouns in English commonly are words like: he, she, it, they, those, my yours, ours, myself, who, what, and where. Pronouns serve the same functions in a sentence as nouns and are diagrammed the same way. To start your diagram, place your subject’s noun on the left side of a long horizontal line and place a perpendicular line through the horizontal line after the noun. The subject of the sentence is done!

A noun clause is a clause that takes the place of a noun. It seems to contain a ‘subject’ and ‘verb’, making it a clause but is dependent on the rest of the sentence to make sense. A good test is that this clause should be replaceable by ‘it’, ‘something’, or ‘someone’. In ‘Whatever you said hurt her feelings’, ‘whatever you said’ is a noun clause. Noun clauses are placed on a pedestal that attaches to where the noun would normally be.

Commands can be confusing since the subject seems nonexistent, but it’s just an invisible ‘you’. Place the (you) in the place for the subject of the sentence for commands.

Predicate and Verbs

The next of the parts of a sentence structure is the predicate. The predicate is what is happening to or being done by the subject; this is done through verbs.Verbs are words that convey action or state of being. Action verbs are words like run, read, play, write, finish, stared, etc. Verbs that show state of being are words like is, are, been, shall, being, etc. and are followed by predicate nominatives. Place verbs (including helping verbs like will or has) on the horizontal line to the right of the perpendicular line. This is the predicate part of the diagram.

Direct Objects and Predicate Nominatives

The last of the basic parts of a sentence structure are direct objects and predicate nominatives. Direct objects are what the subject is doing the action to or what receives the action of the verb. Direct objects can be nouns, pronouns, or noun clauses. Place a perpendicular line that meets the horizontal line after the verb(s) but does not go below the horizontal line. Put the direct object(s) on the horizontal line on the right on the new perpendicular line

Predicate nominatives are nouns that follow verbs that are states of being and are what the subject is, was, will be, etc. Like direct objects, predicate nominatives can be nouns, pronouns, or noun clauses. For predicate nominatives, instead of a perpendicular line, place a left-leaning diagonal line that meets the horizontal line, and place the predicate nominative(s) on the right on the new diagonal line.

Additional Parts

Adverbs

The first of the other parts of a sentence structure are adverbs. Adverbs are words that modify verbs, adjectives, and other adverbs. Adverbs can be words like: quickly, very, necessary, well, badly, towards, a lot, never, and later. Adverbs explain and expand on how much, how far, when, in what way, and how often. They sometimes end in -ly. Adverbs are placed on a diagonal line that attach to the main horizontal line below the verb (get used to this since many parts of speech are attached below the verb). For adverbs that modify adjectives or other adverbs, place the adverb on a diagonal line that attaches to the word it modifies.

An adverb clause is a clause that starts with a subordinating clause and functions as an adverb, which modifies a verb, adverb, or adjective and is movable in the sentence. When adverb clauses are at the start of a sentence, they are set off with a comma. Being dependent clauses, adverb clauses all have a noun and verb and support the main sentence. To check if an adverb clause is a valid clause, remove the subordinating conjunction and see if the words remain to make a full sentence. If they do, you have an adverb clause. 

For clauses, on a separate line beneath the main one, diagram the adverb clause as if it was its own sentence with a horizontal and a perpendicular one separating the noun and the subject. For the subordinating conjunction, place it on a dotted diagonal line that connects the adverb clause’s verb with the main line’s verb.

Articles and Adjectives

Words like ‘a’ and ‘the’ are articles. They modify nouns and pronouns to tell whether they are precise or general. They are a type of adjectives since they modify nouns and pronouns. Adjectives can describe the noun’s size, shape, weight, age, appearance, taste, sound, odor, feel, number, emotion, or can be other descriptors like accurate or alive. Place adjectives on a  diagonal line below the noun they modify.

An adjective phrase is a phrase that serves the purpose of an adjective, modifying a noun or pronoun. It does not contain a verb. An appositive – a noun or phrase that is set aside that expands on a noun or pronoun – can be an adjective phrase. Place the adjective phrase below the noun it modifies.

An adjective clause is a clause that modifies a noun or pronoun. It is not moveable in the sentence and is found directly before or after the noun it modifies. An essential (or restrictive) adjective clause is not set off by commas; for example, ‘He is the boy who speaks little’. A nonessential (or nonrestrictive) adjective clause is set off by commas,  and the sentence can be completed without this clause.

For example: ‘The girl, who has yellow ribbons, is running to school’. Adjective clauses is the other main function for appositives. For adjective clauses, on a separate line beneath the main one, diagram the clause as if it was its own sentence with a horizontal and a perpendicular one separating the noun and the subject. Connect this mini sentence to the main sentence with a dotted line.

Indirect Objects

Indirect objects are nouns that are the recipient of the direct object(s).  Like direct objects, indirect objects can be nouns, pronouns, or noun clauses. When diagramming indirect objects, place them on a short horizontal line below the verb and connect the indirect object to the verb with a diagonal line.

Prepositional Phrases

Prepositions are words that show spatial or temporal relationships between nouns (usually). If a preposition is being used outside of a phrase, place the preposition on the diagonal line below the word it modifies when diagramming. Rarely is a preposition used outside of a prepositional phrase, which is the set of words that includes the preposition, its object, and sometimes adverbs and adjectives as well. 

Most prepositions will fill in the black of the phrase ‘the mouse went ____ the box’. Other prepositions include but, as, and since. These words can be adverbs and/or conjunctions as well, so diagramming the sentence helps to determine their function. When diagramming prepositional phrases, place the object of the preposition on a short horizontal line below the word the prepositional phrase modifies and connect it to the word it modifies with a diagonal line, placing the preposition on the diagonal line.

Conjunctions

Summary

Sentence structure has four main forms: simple, complex, compound, and compound complex. There are other parts of a sentence than just the forms. The 8 parts of a sentence structure are:

• Subject
• Verb/Predicate
• Direct Object/Predicate nominative
• Adverbs
• Articles/Adjectives
• Indirect Objects
• Prepositional Phrases
• Conjunctions