syntactical

Data that are not shared in this manner—say, the exact position of eyes or syntactical rules that make up a well-formulated sentence—can influence behavior, but nonconsciously.

From Scientific American ● Sep. 8, 2023

Oliver Wendell Holmes, who characterized Theodore Roosevelt’s Bull Moose movement as one of “strenuous vagueness,” survived Antietam but might have expired straining to decipher Tuesday’s cascade of falsehoods, rudeness and syntactical tangles.

From Washington Post ● Sep. 30, 2020

The book’s sputtering, flinching style, with its syntactical dead ends and missed connections, feels like both an accommodation to the necessity of language and proof of its inadequacy.

From The New Yorker ● Aug. 20, 2018

First, seemingly thrown by syntactical complexity, it suggests that I should replace “there in a” with “there is a,” a change that would be ungrammatical, but that still leaves me questioning my own stylistic choices.

From Slate ● Feb. 7, 2018

This is plainly implied in the very nature of every form of syntactical agreement; and as plainly contradicted in one half, and probably more, of the definitions usually given of these things.

From The Grammar of English Grammars by Goold Brown