A sentence diagram is a pictorial representation of the
grammatical
In linguistics, grammaticality is determined by the conformity to language usage as derived by the grammar of a particular speech variety. The notion of grammaticality rose alongside the theory of generative grammar, the goal of which is to form ...
structure of a
sentence. The term "sentence diagram" is used more when
teaching
Teaching is the practice implemented by a ''teacher'' aimed at transmitting skills (knowledge, know-how, and interpersonal skills) to a learner, a student, or any other audience in the context of an educational institution. Teaching is closely ...
written language, where sentences are ''diagrammed''. The model shows the relations between words and the nature of sentence structure and can be used as a tool to help recognize which potential sentences are actual sentences.
History
Most methods of diagramming in pedagogy are based on the work of Alonzo Reed and
Brainerd Kellogg
Brainerd Kellogg (August 15, 1834 – January 9, 1920) was born in Champlain, New York. He was a Tutor (1860–1861) and Professor of Rhetoric and English Literature (1861–1868) at Middlebury College in Vermont, United States. From 1868 to 190 ...
. Some teachers continue to use the Reed–Kellogg system in teaching grammar, but others have discouraged it in favor of more modern tree diagrams.
Reed–Kellogg system
Simple sentences in the Reed–Kellogg system are diagrammed according to these forms:

The diagram of a simple sentence begins with a horizontal line called the ''base''. The
subject
Subject ( la, subiectus "lying beneath") may refer to:
Philosophy
*''Hypokeimenon'', or ''subiectum'', in metaphysics, the "internal", non-objective being of a thing
**Subject (philosophy), a being that has subjective experiences, subjective cons ...
is written on the left, the
predicate on the right, separated by a vertical bar that extends through the base. The predicate must contain a
verb
A verb () is a word ( part of speech) that in syntax generally conveys an action (''bring'', ''read'', ''walk'', ''run'', ''learn''), an occurrence (''happen'', ''become''), or a state of being (''be'', ''exist'', ''stand''). In the usual descr ...
, and the verb either requires other sentence elements to complete the predicate, permits them to do so, or precludes them from doing so. The verb and its
object, when present, are separated by a line that ends at the baseline. If the object is a
direct object
In linguistics, an object is any of several types of arguments. In subject-prominent, nominative-accusative languages such as English, a transitive verb typically distinguishes between its subject and any of its objects, which can include bu ...
, the line is vertical. If the object is a
predicate noun or
adjective
In linguistics, an adjective ( abbreviated ) is a word that generally modifies a noun or noun phrase or describes its referent. Its semantic role is to change information given by the noun.
Traditionally, adjectives were considered one of the ...
, the line looks like a
backslash, \, sloping toward the subject.
Modifiers
In linguistics, a modifier is an optional element in phrase structure or clause structure which ''modifies'' the meaning of another element in the structure. For instance, the adjective "red" acts as a modifier in the noun phrase "red ball", provi ...
of the subject, predicate, or object are placed below the baseline:

Modifiers, such as
adjective
In linguistics, an adjective ( abbreviated ) is a word that generally modifies a noun or noun phrase or describes its referent. Its semantic role is to change information given by the noun.
Traditionally, adjectives were considered one of the ...
s (including articles) and
adverb An adverb is a word or an expression that generally modifies a verb, adjective, another adverb, determiner, clause, preposition, or sentence. Adverbs typically express manner, place, time, frequency, degree, level of certainty, etc., answering q ...
s, are placed on slanted lines below the word they modify. Prepositional phrases are also placed beneath the word they modify; the preposition goes on a slanted line and the slanted line leads to a horizontal line on which the object of the preposition is placed.
These basic diagramming conventions are augmented for other types of sentence structures, e.g. for
coordination
Coordination may refer to:
* Coordination (linguistics), a compound grammatical construction
* Coordination complex, consisting of a central atom or ion and a surrounding array of bound molecules or ions
* Coordination number or ligancy of a centr ...
and
subordinate clauses.
Constituency and dependency
The connections to modern principles for constructing parse trees are present in the Reed–Kellogg diagrams, although Reed and Kellogg understood such principles only implicitly. The principles are now regarded as the constituency relation of
phrase structure grammar
The term phrase structure grammar was originally introduced by Noam Chomsky as the term for grammar studied previously by Emil Post and Axel Thue ( Post canonical systems). Some authors, however, reserve the term for more restricted grammars in ...
s and the dependency relation of
dependency grammar
Dependency grammar (DG) is a class of modern grammatical theories that are all based on the dependency relation (as opposed to the ''constituency relation'' of phrase structure) and that can be traced back primarily to the work of Lucien Tesniè ...
s. These two relations are illustrated here adjacent to each other for comparison, where D means Determiner, N means Noun, NP means Noun Phrase, S means Sentence, V means Verb, VP means Verb Phrase and IP means Inflectional Phrase.

Constituency is a one-to-one-or-more relation; every word in the sentence corresponds to one or more nodes in the tree diagram. Dependency, in contrast, is a one-to-one relation; every word in the sentence corresponds to exactly one node in the tree diagram. Both parse trees employ the convention where the category acronyms (e.g. N, NP, V, VP) are used as the labels on the nodes in the tree. The one-to-one-or-more constituency relation is capable of increasing the amount of sentence structure to the upper limits of what is possible. The result can be very "tall" trees, such as those associated with
X-bar theory
In linguistics, X-bar theory is a model of phrase-structure grammar and a theory of syntactic category formation that was first proposed by Noam Chomsky in 1970Chomsky, Noam (1970). Remarks on Nominalization. In: R. Jacobs and P. Rosenbaum (eds.) ...
. Both constituency-based and dependency-based theories of grammar have established traditions.
Reed–Kellogg diagrams employ both of these modern tree generating relations. The constituency relation is present in the Reed–Kellogg diagrams insofar as subject, verb, object, and/or predicate are placed equi-level on the horizontal base line of the sentence and divided by a vertical or slanted line. In a Reed–Kellogg diagram, the vertical dividing line that crosses the base line corresponds to the binary division in the constituency-based tree (S → NP + VP), and the second vertical dividing line that does not cross the baseline (between verb and object) corresponds to the binary division of VP into verb and direct object (VP → V + NP). Thus the vertical and slanting lines that cross or rest on the baseline correspond to the constituency relation. The dependency relation, in contrast, is present insofar as modifiers dangle off of or appear below the words that they modify.
Functional breakdown
A sentence may also be broken down by functional parts: subject, object, adverbial, verb (predicator).
The subject is the owner of an action, the verb represents the action, the object represents the recipient of the action, and the adverbial qualifies the action. The various parts can be phrases rather than individual words.
See also
*
Parse tree
A parse tree or parsing tree or derivation tree or concrete syntax tree is an ordered, rooted tree that represents the syntactic structure of a string according to some context-free grammar. The term ''parse tree'' itself is used primarily in comp ...
*
Unparser
In computing, an unparser is a system that constructs a set of characters or image components from a given parse tree.''Software Science and Engineering'' edited by Ikuo Nakata 1991 page 168
An unparser is in effect the reverse of a traditional ...
References
Further reading
Primary sources
* Clark, W. (1847). ''A practical grammar: In which words, phrases & sentences are classified according to their offices and their various relationships to each another''. Cincinnati: H. W. Barnes & Company.
* Reed, A. and B. Kellogg (1877)
''Higher Lessons in English''
* Reed, A. and B. Kellogg (1896). ''Graded Lessons in English: An Elementary English Grammar''. .
* Reed, A. and B. Kellogg (1896)
''Graded Lessons in English: An Elementary English Grammar Consisting of One Hundred Practical Lessons, Carefully Graded and Adapted to the Class-Room''
Critical sources
* Kitty Burns Florey (2006). ''Sister Bernadette's Barking Dog''. Melville House Publishing. .
* Mazziotta, N. (2016)
"Drawing syntax before syntactic trees: Stephen Watkins Clark's sentence diagrams (1847)" ''Historiographia Linguistica'', 43(3), 301–342. .
External links
by Elizabeth O'Brien
GrammarBrain - Sentence Diagramming RulesSenGram an
iPhone and
iPad app
The App Store is an app store platform, developed and maintained by Apple Inc., for mobile apps on its iOS and iPadOS operating systems. The store allows users to browse and download approved apps developed within Apple's iOS Software ...
that presents sentence diagrams as puzzles.
Diagramming Sentences including many advanced configurations
SenDraw a
computer program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components.
A computer progra ...
that specializes in Reed–Kellogg diagrams
* {{Cite book , first1=Marye , last1=Hefty , author2=Sallie Ortiz , author3=Sara Nelson , year=2008 , title=Sentence Diagramming: A Step-by-Step Approach to Learning Grammar Through Diagramming , url=http://www.pearsonhighered.com/educator/product/Sentence-Diagramming-A-StepbyStep-Approach-to-Learning-Grammar-Through-Diagramming/9780205551262.page , location=New York , publisher=Pearson/Longman , isbn=9780205551262 , oclc=127114018
Diagrams
English grammar
Grammar
Syntax
Generative syntax