Sentence diagram generator
Break an English sentence into its parts — subject, predicate, objects and modifiers — and render the analysis as a clean tree. Start from a template, swap in your sentence, and export. Nothing is uploaded.
One step per line. Indent two spaces to branch beneath the line above.
How to diagram a sentence here
Load a template above, then swap in your own sentence: keep the top-level split into subject and predicate, and replace the words at the leaves with yours, each labelled with its part of speech. Every phrase — noun phrase, verb phrase, prepositional phrase — gets its own branch, so the grammar becomes visible structure. If Mermaid syntax gets in the way, switch on Outline mode and type the same breakdown as an indented list: each line becomes a node, each indent a branch.
The tree re-renders as you type and exports as a crisp SVG or PNG — ready for a worksheet, a slide or your grammar notes.
A structure tree, not a Reed-Kellogg baseline
Classic Reed-Kellogg diagrams put the subject and verb on a horizontal base line and hang modifiers off slanted lines below it. This tool draws a different picture: a constituency-style tree that splits the sentence into subject and predicate, then into phrases, then into words. The grammatical analysis is the same — only the notation differs — and the tree form is what modern linguistics and most grammar courses use.
If an assignment specifically requires Reed-Kellogg notation, use the tree to get the analysis right first — identifying the subject, verb, objects and modifiers is the hard part — then transcribe it onto the base line by hand.
What to break out, in order
Start with the two-way split every sentence has: the complete subject (who or what the sentence is about) and the complete predicate (what is said about it). Inside the predicate, find the verb, then any objects or complements. Then attach modifiers where they belong: articles and adjectives under the noun they describe, adverbs under the verb, and prepositional phrases under whatever they modify.
Compound sentences split first at the coordinating conjunction into independent clauses; complex sentences separate the dependent clause — with its subordinating conjunction — from the main clause. The example trees above show all three patterns.
Diagram types
Frequently asked questions
How do I diagram a sentence with this tool?
Load a template, replace the words at the leaves with your sentence, and keep the structure: sentence at the root, subject and predicate below it, then phrases and words. It renders live, and you can export SVG or PNG.
Is this a Reed-Kellogg sentence diagrammer?
No — it draws sentence structure trees, not Reed-Kellogg base lines. The analysis (subject, verb, objects, modifiers) is identical; the picture is a top-down tree, which is the notation modern grammar teaching and linguistics mostly use.
Does it parse my sentence automatically?
No. This is a diagram editor, not a grammar checker: you decide the analysis and the tool renders it. That is deliberate — it stays deterministic and free, and your text never leaves the browser. The templates give you the standard patterns to edit.
Can I use it for teaching or homework?
Yes. Teachers export PNG trees for worksheets and slides; students hand in SVG or PNG diagrams or share the editable source. There is no signup and no watermark.
What if a word appears twice in the sentence?
Give each occurrence its own node id — for example D1 and D2 for two instances of "the". The quoted label text can repeat; the ids before the brackets must be unique.