What is a sentence diagram generator?

A sentence diagram generator is a tool that takes an English sentence as plain text and draws a visual diagram of its grammatical structure. This generator draws Reed-Kellogg diagrams — the classic schoolbook layout with a horizontal baseline for the subject and verb, slanted lines for modifiers, and stilts for subordinate clauses.

How do you diagram a sentence using the Reed-Kellogg method?

Start with a horizontal baseline. Put the subject on the left and the simple verb on the right, separated by a vertical line that crosses the baseline. Add a direct object after the verb, separated by a vertical line that does NOT cross the baseline. Slant adjectives and adverbs diagonally below the word they modify. Put prepositional phrases on a slanted line with a horizontal extension carrying the object of the preposition. Lift subordinate clauses onto a stilt connected to whatever they modify. The sentence diagram generator follows these rules automatically.

What parts of speech does the diagram label?

Every part of speech in a standard English grammar course: nouns and pronouns (subjects, direct and indirect objects, objects of prepositions), verbs (action, linking, helping), adjectives, adverbs, prepositions, coordinating and subordinating conjunctions, interjections, and articles. Verbals — gerunds, infinitives, and participles — sit on their own lines per Reed-Kellogg convention.

Can it diagram compound and complex sentences?

Yes. Compound sentences are drawn with two or more parallel horizontal baselines joined by a dashed line carrying the coordinating conjunction (and, but, or, nor, for, yet, so). Complex sentences with subordinate clauses put the subordinate clause on a stilt below the main baseline, with the subordinator (because, although, when, if, since) on the dashed connector. Compound-complex sentences combine both patterns in one diagram.

Can I diagram questions and imperative sentences?

Yes. Interrogative sentences are rearranged into declarative order on the baseline — 'Did the dog bark?' becomes a diagram with 'dog' as subject, 'did bark' as verb. Imperative sentences use an understood 'you' as the subject in parentheses. Both follow the Reed-Kellogg conventions taught in classical and traditional grammar curricula.

Can I generate blank worksheets for student practice?

Yes. Add 'blank worksheet' or 'unlabeled' to your prompt and the sentence diagram generator returns the geometry — baselines, modifier slants, prepositional-phrase lines, stilts — with empty slots for students to fill in. Pair it with the labeled version as an answer key. Useful for ELA classrooms, ESL practice, and homeschool curricula.

How long are the sentences it can handle?

About 40 words is the practical limit for a single Reed-Kellogg diagram before the slants and stilts overlap. For longer compound-complex sentences, split into clauses or describe the structure you want and the AI will lay it out as readably as the geometry allows.

Does it support languages other than English?

Reed-Kellogg sentence diagramming is an English-grammar convention. The tool focuses on English. For other languages with phrase structure trees (Spanish, German, Japanese, Mandarin, etc.), use the Vizcept syntax tree generator, which draws linguistics-style trees instead of Reed-Kellogg diagrams.

What file formats can I export?

The free plan exports a 2K PNG with a small watermark. Paid plans export 4K PNG, transparent PNG (for slide-deck overlays), and print-ready PDF for classroom handouts. Each format is sized for projection, printing, and screen reading.

Is the sentence diagram generator free?

Sign-up is free and includes starter credits — enough to generate several Reed-Kellogg diagrams without paying. Each generation uses credits. Monthly, yearly, and lifetime plans are available for teachers, tutors, and homeschool parents who diagram sentences every week.

AI Sentence Diagram Generator

Sentence Diagram Generator for Any English Sentence

Paste an English sentence and the AI draws a labeled Reed-Kellogg sentence diagram — subject, verb, direct object, modifiers, prepositional phrases, and subordinate clauses all on the right lines, ready for grammar class, ELA worksheets, and homeschool review.

Reed-Kellogg layoutOriginal wording preservedPrintable PNG worksheets

Sentence Diagram Generator

Aspect Ratio

Quality

5 credits/generation

Free trial: 5 credits, 2K resolution with watermark

Reed-Kellogg sentence diagram for a simple SVO sentence with modifiers

Example Sentence Diagrams

Diagram a Sentence Without Drawing the Lines Yourself

No protractor. No graph paper. No drag-and-drop editor.

Stop redrawing baselines and slanted modifier lines by hand. Type the sentence you need to diagram, choose Reed-Kellogg style or a blank worksheet, and the sentence diagram generator returns a printable image with every word in the right place — for English, ELA, ESL, and homeschool grammar lessons.

Diagram a Sentence Free

Type or Paste an English Sentence

Drop in a simple, compound, complex, or compound-complex sentence — up to about 40 words. Add a short note if you want a color-coded parts-of-speech version, a blank worksheet for students, or extra labels above each word.

AI Parses the Sentence and Builds the Diagram

The sentence diagrammer identifies subject and verb, draws the main horizontal baseline, places direct and indirect objects after the verb, slants modifiers under their target words, and lifts subordinate clauses onto a stilted second baseline — preserving the original wording at every step.

Download the Worksheet as PNG or PDF

Export a 4K PNG for projecting in class, a print-ready PDF for handouts, or a transparent PNG to drop into your slide deck or Google Doc. Pair labeled answer keys with blank versions for a complete grammar worksheet.

One Sentence Diagram Generator, Three Classroom Workflows

ELA Teachers · Homeschool Parents · Tutors and Students

The same Reed-Kellogg sentence diagram generator handles middle-school grammar warm-ups, classical homeschool curricula, and one-on-one ESL tutoring — without spending a planning period on a single diagram.

Students and ESL Learners

Middle school, high school, and college English

You can identify the subject and verb in your head — you just need a clean Reed-Kellogg diagram on the page. Paste any English sentence and get a labeled worksheet for grammar homework, SAT writing review, or ESL self-study in 30 seconds.

Handles relative clauses, gerunds, infinitives, and participles
Renders in under 30 seconds — works at 11 PM before class
Free credits on sign-up — no payment info required

Diagram Your First Sentence

Grammar Teachers and ELA Instructors

K-12, ESL, and college composition

Build a full week of grammar warm-ups, sentence diagramming practice, and answer keys in one prep period. Generate a labeled version for your slide deck and a blank version for students — from the same sentence, in one click.

Generate labeled answer keys and blank worksheets side by side
Drop straight into Google Slides, Canva, or a printed packet
Consistent Reed-Kellogg style across every worksheet

Make a Grammar Worksheet

Homeschool Parents and Tutors

Classical education and one-on-one tutoring

Classical curricula like Shurley, Easy Grammar, and Analytical Grammar rely on sentence diagramming — and so do most diagnostic grammar tutors. The sentence diagram maker keeps your lesson plan moving when you hit a sentence you don't want to draw freehand.

Matches Reed-Kellogg conventions used in classical curricula
Side-by-side worksheets for parent answer key + child practice
Color-coded parts of speech for ADHD and visual learners

Build a Lesson Worksheet

Sentence Diagrams Generated by AI

Real classroom sentences, real Reed-Kellogg diagrams

Every diagram below was generated from a plain-text sentence and a short style hint. Click any example to load the prompt and try a sentence of your own.

Simple SVO Sentence

Subject, verb, direct object, and adjective modifier

Compound Sentence with Conjunction

Two independent clauses joined by 'and'

Complex Sentence with Relative Clause

Relative pronoun 'that' linking a subordinate clause

Complex Sentence with Subordinate Clause

Adverbial clause introduced by 'because'

Interrogative Sentence

Question rearranged to declarative order on the baseline

Blank Reed-Kellogg Worksheet

Unlabeled diagram for student practice

What Makes This Sentence Diagram Generator Different

Not Another Random Word-Tagger

Most online sentence diagrammers label parts of speech in a list and call it done. This Reed-Kellogg sentence diagram generator draws the actual baseline, the slanted modifier lines, the prepositional phrase connectors, and the subordinate clause stilts — and keeps the original sentence wording on every line.

Real Reed-Kellogg Lines

Baseline, Slants, and Stilts

Subject and verb sit on a horizontal baseline with a vertical line between them. Direct objects use a vertical line that does not cross the baseline. Modifiers slant diagonally under their target word. Subordinate clauses go on a stilt — exactly the geometry English grammar textbooks have used since 1877.

Start free, upgrade when the worksheet packet grows

Every account gets free credits on sign-up. Need more Reed-Kellogg diagrams for a unit, a full semester of grammar warm-ups, or a paid teacher resource? Pick a plan that fits the size of your workload.

Student or teacher? Apply for an education discount

Apply now

How English and ESL Teachers Actually Use It

Feedback from K-12 grammar teachers, ESL instructors, classical homeschool parents, and middle-school students who used to draw every Reed-Kellogg diagram by hand.

Rebecca Whitfield

7th Grade ELA Teacher, Asheville, NC

I run a 'Diagram of the Day' warm-up. Drawing each one by hand was taking 25 minutes a sentence. Now I generate the labeled version for the projector and a blank worksheet for the students in two clicks.

Mateo Reyes

9th Grader, Sacramento, CA

My English teacher gives us five Reed-Kellogg sentences a week. I used to fight with pencil lines on graph paper. Now I diagram each sentence first, then redraw it neatly knowing where everything goes.

Sister Catherine Walsh

Classical Homeschool Parent, Pittsburgh, PA

We follow the Memoria Press grammar program. The sentence diagram generator handles every sentence type in the curriculum and matches the textbook conventions — so my answer keys look exactly like the back of the book.

Rebecca Whitfield

7th Grade ELA Teacher, Asheville, NC

I run a 'Diagram of the Day' warm-up. Drawing each one by hand was taking 25 minutes a sentence. Now I generate the labeled version for the projector and a blank worksheet for the students in two clicks.

Mateo Reyes

9th Grader, Sacramento, CA

My English teacher gives us five Reed-Kellogg sentences a week. I used to fight with pencil lines on graph paper. Now I diagram each sentence first, then redraw it neatly knowing where everything goes.

Sister Catherine Walsh

Classical Homeschool Parent, Pittsburgh, PA

We follow the Memoria Press grammar program. The sentence diagram generator handles every sentence type in the curriculum and matches the textbook conventions — so my answer keys look exactly like the back of the book.

Rebecca Whitfield

7th Grade ELA Teacher, Asheville, NC

I run a 'Diagram of the Day' warm-up. Drawing each one by hand was taking 25 minutes a sentence. Now I generate the labeled version for the projector and a blank worksheet for the students in two clicks.

Mateo Reyes

9th Grader, Sacramento, CA

My English teacher gives us five Reed-Kellogg sentences a week. I used to fight with pencil lines on graph paper. Now I diagram each sentence first, then redraw it neatly knowing where everything goes.

Sister Catherine Walsh

Classical Homeschool Parent, Pittsburgh, PA

We follow the Memoria Press grammar program. The sentence diagram generator handles every sentence type in the curriculum and matches the textbook conventions — so my answer keys look exactly like the back of the book.

Rebecca Whitfield

7th Grade ELA Teacher, Asheville, NC

I run a 'Diagram of the Day' warm-up. Drawing each one by hand was taking 25 minutes a sentence. Now I generate the labeled version for the projector and a blank worksheet for the students in two clicks.

Mateo Reyes

9th Grader, Sacramento, CA

My English teacher gives us five Reed-Kellogg sentences a week. I used to fight with pencil lines on graph paper. Now I diagram each sentence first, then redraw it neatly knowing where everything goes.

Sister Catherine Walsh

Classical Homeschool Parent, Pittsburgh, PA

We follow the Memoria Press grammar program. The sentence diagram generator handles every sentence type in the curriculum and matches the textbook conventions — so my answer keys look exactly like the back of the book.

Hannah Lin

ESL Instructor, International School Shanghai

My intermediate ESL learners struggle with English word order. The color-coded part-of-speech diagrams make the subject-verb-object structure obvious in a way that bullet-point grammar rules never did.

Dr. Owen Bradshaw

Composition Director, Liberal Arts College

Our freshmen come in unable to identify their own sentence subjects. I now hand out Reed-Kellogg diagrams of their own thesis statements. The structural problems show up visually, and revisions follow.

Priya Anand

Grammar Tutor, Bay Area

I tutor students on writing-section SAT and ACT prep. Generating a quick sentence diagram during a session helps them see the difference between a misplaced modifier and a normal adjective. Worth the credits.

Hannah Lin

ESL Instructor, International School Shanghai

My intermediate ESL learners struggle with English word order. The color-coded part-of-speech diagrams make the subject-verb-object structure obvious in a way that bullet-point grammar rules never did.

Dr. Owen Bradshaw

Composition Director, Liberal Arts College

Our freshmen come in unable to identify their own sentence subjects. I now hand out Reed-Kellogg diagrams of their own thesis statements. The structural problems show up visually, and revisions follow.

Priya Anand

Grammar Tutor, Bay Area

I tutor students on writing-section SAT and ACT prep. Generating a quick sentence diagram during a session helps them see the difference between a misplaced modifier and a normal adjective. Worth the credits.

Hannah Lin

ESL Instructor, International School Shanghai

My intermediate ESL learners struggle with English word order. The color-coded part-of-speech diagrams make the subject-verb-object structure obvious in a way that bullet-point grammar rules never did.

Dr. Owen Bradshaw

Composition Director, Liberal Arts College

Our freshmen come in unable to identify their own sentence subjects. I now hand out Reed-Kellogg diagrams of their own thesis statements. The structural problems show up visually, and revisions follow.

Priya Anand

Grammar Tutor, Bay Area

I tutor students on writing-section SAT and ACT prep. Generating a quick sentence diagram during a session helps them see the difference between a misplaced modifier and a normal adjective. Worth the credits.

Hannah Lin

ESL Instructor, International School Shanghai

My intermediate ESL learners struggle with English word order. The color-coded part-of-speech diagrams make the subject-verb-object structure obvious in a way that bullet-point grammar rules never did.

Dr. Owen Bradshaw

Composition Director, Liberal Arts College

Our freshmen come in unable to identify their own sentence subjects. I now hand out Reed-Kellogg diagrams of their own thesis statements. The structural problems show up visually, and revisions follow.

Priya Anand

Grammar Tutor, Bay Area

I tutor students on writing-section SAT and ACT prep. Generating a quick sentence diagram during a session helps them see the difference between a misplaced modifier and a normal adjective. Worth the credits.

James Whitaker

Special-Education ELA Teacher, Birmingham, UK

My students need visual scaffolding for grammar. The blank-worksheet version of each diagram gives them a structure to fill in — they hit the right line without me redrawing 30 worksheets a week.

Olivia Park

Curriculum Designer, Online Tutoring Startup

I built a 40-lesson sentence-diagramming module. Drafting every diagram in Illustrator would have eaten a month. Generating with the sentence diagrammer and cleaning up in SVG took a week.

Father Michael O'Reilly

Classical Education Headmaster, Dublin

Our school still teaches Latin and English grammar via sentence diagramming. The tool keeps the Reed-Kellogg geometry our older teachers still use — and saves my younger staff from learning to draw it on the whiteboard.

James Whitaker

Special-Education ELA Teacher, Birmingham, UK

My students need visual scaffolding for grammar. The blank-worksheet version of each diagram gives them a structure to fill in — they hit the right line without me redrawing 30 worksheets a week.

Olivia Park

Curriculum Designer, Online Tutoring Startup

I built a 40-lesson sentence-diagramming module. Drafting every diagram in Illustrator would have eaten a month. Generating with the sentence diagrammer and cleaning up in SVG took a week.

Father Michael O'Reilly

Classical Education Headmaster, Dublin

Our school still teaches Latin and English grammar via sentence diagramming. The tool keeps the Reed-Kellogg geometry our older teachers still use — and saves my younger staff from learning to draw it on the whiteboard.

James Whitaker

Special-Education ELA Teacher, Birmingham, UK

My students need visual scaffolding for grammar. The blank-worksheet version of each diagram gives them a structure to fill in — they hit the right line without me redrawing 30 worksheets a week.

Olivia Park

Curriculum Designer, Online Tutoring Startup

I built a 40-lesson sentence-diagramming module. Drafting every diagram in Illustrator would have eaten a month. Generating with the sentence diagrammer and cleaning up in SVG took a week.

Father Michael O'Reilly

Classical Education Headmaster, Dublin

Our school still teaches Latin and English grammar via sentence diagramming. The tool keeps the Reed-Kellogg geometry our older teachers still use — and saves my younger staff from learning to draw it on the whiteboard.

James Whitaker

Special-Education ELA Teacher, Birmingham, UK

My students need visual scaffolding for grammar. The blank-worksheet version of each diagram gives them a structure to fill in — they hit the right line without me redrawing 30 worksheets a week.

Olivia Park

Curriculum Designer, Online Tutoring Startup

I built a 40-lesson sentence-diagramming module. Drafting every diagram in Illustrator would have eaten a month. Generating with the sentence diagrammer and cleaning up in SVG took a week.

Father Michael O'Reilly

Classical Education Headmaster, Dublin

Our school still teaches Latin and English grammar via sentence diagramming. The tool keeps the Reed-Kellogg geometry our older teachers still use — and saves my younger staff from learning to draw it on the whiteboard.

Sentence Diagram Generator — Common Questions

FAQ

Your First Sentence Diagram, Free

Paste any English sentence. Get a Reed-Kellogg diagram with subject, verb, modifiers, and clauses in 30 seconds. No graph paper, no protractor, no credit card.

Diagram a Sentence Now See Pricing Plans