Languages differ from each other in various respects, e.g., in their sentence structure (syntax), word structure (morphology), sound structure (phonology) and vocabulary (lexicon). The extent and limits of variation are a challenging puzzle.
Human languages are also dynamic: they change over time. This group investigates language variation and change from a theoretical, sociolinguistic and diachronic perspective.
The theoretical-structural perspective
This subgroup is mainly concerned with the study of linguistic diversity and the way it is encoded in the cognitive computational system that generates language structures, i.e. grammar.
The questions to which the members try to give an answer include: what are the limits to linguistic variation? Where in the grammar are different dimensions of linguistic diversity encoded? Is the encoding of small linguistic differences (microvariation) fundamentally different from the encoding of major linguistic differences (macrovariation)? Which parts of human language structures are invariant (i.e., universal) and what is the relation between language universals and the L0 stage of language, known as Universal Grammar?
This subgroup mainly works on the question how language variation comes to existance and develops/changes in multilingual and multicultural societies. The main research questions for this subgroup are: How and why do new language varieties arise in language contact situations, and how stable are these varieties? Under which circumstances will languages be under pressure and risk disappearance? What are the consequences of multilingualism and language contact for a linguistic community, and for the individual speaker?
The diachronic perspective
This subgroup aims to identify the historical sources of linguistic divergence and convergence: how and why have related languages grown apart? How did features shared by unrelated languages arise?
Research focusing on these three perspectives jointly, allow us to address the central question: how do internal factors (grammar) and external factors (linguistic and social interaction in linguistic communities, and the factor time) interact, and what is their role in linguistic diversity and change?