Syntax Tree Generator | How Language Builds Meaning
How Sentences Grow
The foundation of language is the idea that meaning is made by words in combination with each other. We add words to other words to explain our world. The tool on this page is a syntax tree generator to help you visualize this abstract combination. For example, the word “fuzzy” in isolation does not carry much weight on its own, but if you combine it with the word “cat” to make “Persian cat,” you have made something with more meaning than the two words in isolation. If we add another word, we can then take “Persian cat” and combine it with “fuzzy” to get “fuzzy Persian cat” — something with even more meaning.
Everything we add to our sentence sequence gives more information in our internal conception. Linguist Noam Chomsky called this Merge and defined it as the foundation of human grammar.
Merge is an operation that combines two things at a time, never more than that, and what it produces then becomes the input for the next combination. This is, by mathematical definition, recursive; each step builds on the last and does so in a structured manner. That is how something as complex as language grows from something so simple.
Watch it accumulate. “Cat” merges with “Persian” to give “Persian cat.” That merges with “fuzzy” to give “fuzzy Persian cat,” and that merges with “the” to give “the fuzzy Persian cat.” Separately, “is” merges with “sleeping” to give “is sleeping.” Those two finished pieces then merge with each other: “The fuzzy Persian cat is sleeping.” To place the cat, we build “the sun” from “the” and “sun,” merge that with “in” to get “in the sun,” and merge the result with the sentence we already had. Finally “rumpled” merges with the cat itself, and we end with “The rumpled fuzzy Persian cat is sleeping in the sun.” Our ending sentence is worlds of complexity away from the two words we started with.
We can illustrate the above complexity pictorially. Interestingly, the way our words came together is different from the way we speak or write them. This tool, or syntactic tree, is a diagram of how words combine in meaning, presented as a pictorial flow of information, added step by step.
When we look at a syntactic tree, we see the output as an illustration of Merge. The bottom is where we start, in our example, “fuzzy” and “cat”, and it then ends at the top with our finished sentence. As in any language, the order of words and the order of Merge produce different meanings. Language choice is deliberate.
Chomsky argues that this complexity of Merge is what makes human language unique. As a species, all human languages follow this pattern of communication. We have a finite vocabulary that can be combined to create infinite possible sentences; there is no end to adding units together to generate new meanings.
This syntax tree generator tool was made to illustrate and simplify the concept of Merge. Try creating a sequence of your own. The meaning does not matter as much as the process.
How to Use the Syntactic Merge Lab
Click words in the lexicon panel on the left. They appear in the workspace on the right. Hover any word to see the features it carries.
Click two objects in the workspace to select them, then press the Merge button. The button shows you what the merge will produce before you commit.
Build outward from the smallest pieces. A determiner like the is not a complete phrase until it has merged with a noun, so merge the with cat first, then merge that result with the verb.
Merge never refuses. If two things cannot legally combine, the lab builds the object anyway, marks it in red, and explains what went wrong. That is the point, rather than a malfunction: Merge is free, and grammar is the separate step that filters what Merge produces.
Under the tree, a verdict tells you whether your derivation converges, and lists what is still missing if it does not.
To move a constituent, select a whole object, then click a piece inside its tree. That is Internal Merge, the operation behind questions. Try building Ø the cat chases what, then moving what to the front.
The tabs:
- Tree shows the structure as it builds
- Sets show the same structure as pure set notation, plus labeled brackets
- Algebra covers the mathematical properties of Merge
- Census builds every possible bracketing of your words, checks each one, and reports how many survive
To add your own words, type into the Custom field, choose a category, and press Add. Verbs let you choose transitive or intransitive; determiners can be marked as movable question words.
From TedEd talk by Cameron Morin “What Do All Languages Have in Common/”