We aim at explicating human linguistic competence. Carefully observing empirical data from various individual languages, we study what the universal aspects of language are, how a language can change diachronically and vary synchronically, and how it is acquired, in terms of syntax, morphology, phonology, and semantics. Our special emphasis is on the following fields:

(1)Morphosyntax:

(2)Lexical Semantics:

To study the semantic structure of predicates such as verbs, nouns and adjectives, and to elucidate which aspects of the semantic structure have syntactic  reflections.

(3)Diachronic Syntax/Comparative Syntax/Psycholinguistics:

(i) To study the nature of diachronic change and synchronic diversity of languages, (ii) to propose a theory of the language faculty that allows diachronic change and synchronic diversity, and (iii) to justify the theory by logical thinking, corpus studies, and methodologies of experimental psychology. (including a collaborative work with the department of Visual Cognition)

For these purposes, we are engaged in the interdisciplinary research project called "Language Change and Language Variation Research Unit (LCLVRU),” which has been organized to pursue our aims from multiple perspectives. See the following URLs for the LCLVRU and other activities lead by the staff of our lab:
http://ling.human.is.tohoku.ac.jp/change/home.html
https://w3.tohoku.ac.jp/frid-en/project/understanding-the-brain-mechanism-of-language-computation-from-analyzing-the-communication-signals-of-birds/