Comparative syntax investigates structural similarities and differences across languages or varieties. It asks which proposed grammatical relationships generalize, which vary, and whether apparently different constructions realize a shared organization. Comparable meanings, contexts and data-collection methods are needed before a difference can be assigned to grammar.[ref]
Research homepage by Julianne Doner. Comparative Syntax and Clausal Architecture, cross-language comparison and correlated properties
For an original toy example, suppose one grammar expresses “A acts on B” with order
A V B, while another uses A B V. Reversing the participants changes the intended meaning, whereas changing the position of V follows the grammatical template. This separates word order from the participants' thematic roles. Actual comparison examines more than one translated sentence: questions, embedded clauses and other environments can distinguish a superficial ordering similarity from a general structural account. New to topics? Read the docs here!