What Is Diagramming Sentences?
Every sentence has two parts, a subject and a predicate. A diagram is a graphic that shows the two parts of a sentence and the relationship of every word in the sentence to either the subject or the predicate. Because sentences vary in length and complexity, so does diagramming a sentence. Diagramming was a fun way to learn the grammatical construction of sentences. It was like solving a puzzle, and went hand in hand with instruction in grammar usage and parts of speech, like nouns, verbs, adjectives, adverbs, prepositions, conjunctions, and interjections.
Diagramming was taught systematically beginning by at least 5th grade and continued until 8th. It was also continued in the freshman year of high school. The textbook series that we used then was Voyages in English, published by Loyola University Press of Chicago. Below are some examples from textbooks of that era.
A Lesson on Types of Sentences: Fifth Grade Textbook
Models of Diagrammed Sentences: Eighth Grade Textbook
Believe it or not, "The Pledge of Allegiance" is one sentence. My dad once diagrammed it for me as proof positive. I took his word that he had done it correctly. The example below, which I found here, shows various versions that are possible.
I think learning to diagram sentences was a valuable tool for learning to think logically and for understanding English grammar. It also helped me learn other languages, because it familiarized me with parts of speech and their relationships to subjects and predicates, even when the other languages were more inflected than English.
Here is a link with more links to websites that have information on Diagramming Sentences.
I'll say something about writing paragraphs in a future post.