*Article* **A Fuzzy Grammar for Evaluating Universality and Complexity in Natural Language**

**Adrià Torrens-Urrutia 1,\*,†, María Dolores Jiménez-López 1,†, Antoni Brosa-Rodríguez 1,† and David Adamczyk 2,†**


† These authors contributed equally to this work.

**Abstract:** The paper focuses on linguistic complexity and language universals, which are two important and controversial issues in language research. A Fuzzy Property Grammar for determining the degree of universality and complexity of a natural language is introduced. In this task, the Fuzzy Property Grammar operated only with syntactic constraints. Fuzzy Natural Logic sets the fundamentals to express the notions of universality and complexity as evaluative expressions. The Fuzzy Property Grammar computes the constraints in terms of weights of universality and calculates relative complexity. We present a proof-of-concept in which we have generated a grammar with 42B syntactic constraints. The model classifies constraints in terms of low, medium, and high universality and complexity. Degrees of relative complexity in terms of similarity from a correlation matrix have been obtained. The results show that the architecture of a Universal Fuzzy Property Grammar is flexible, reusable, and re-trainable, and it can easily take into account new sets of languages, perfecting the degree of universality and complexity of the linguistic constraints as well as the degree of complexity between languages.

**Keywords:** linguistic universals; linguistic complexity; evaluative expressions; fuzzy grammar; linguistic gradience; linguistic constraints

**MSC:** 03B65
