Sumti

Sumti is a linguistic term in the constructed language Lojban describing the referents that fill the argument slots of a bridi, or predicate sentence. In Lojban, a bridi expresses a relationship or state, and its places (often called places 1, 2, 3, etc.) are the roles that sumti fill. The sumti provide the concrete entities, times, places, or properties that the bridi is about, while the bridi’s selbri encodes the predicate or relation.

Sumti come in several forms. Simple sumti are standalone expressions such as pronouns or proper names that designate discourse referents directly. Descriptive or structured sumti use descriptive phrases to name a referent, typically formed with constructs like lo … or le … to refer to an instance or a definite set described by a phrase. For example, lo gerku can mean “a dog” (an instance of the set of dogs), and le gerku can mean “the dog.” There are also further forms used to stand in for referents in more complex sentences, including placeholders and built-up phrases.

A hallmark of sumti is that they map to the bridi’s places in a generally left-to-right order, though ellipsis, anaphora, and context can modify which sumti fill which places. The word zo'e functions as a universal placeholder, meaning “whatever it is,” and is used when the exact referent is not specified or is not important for the assertion.

Together, sumti and selbri form the core of Lojban syntax: sumti provide the referential real-world content, and selbri express the predicate or relation that connects those referents.