Volcano of classifying magmatic volcanoes is by their frequency of eruption, with those that erupt regularly called active, those that have erupted in historical times but are now quiet called dormant or inactive, and those that have not erupted in historical times called extinct. However, these popular classifications—extinct in particular—are practically meaningless to scientists. They use classifications which refer to a particular volcano's formative and eruptive processes and resulting shapes. There is no consensus among volcanologists on how to define an "active" volcano. The lifespan of a volcano can vary from months to several million years, making such a distinction sometimes
Active–stative language often show complications and special cases ("pure" active alignment is an ideal). Thus, the terminology used is rather flexible. Active languages are termed also "active–stative" or even "nominative–absolutive". The terms "agentive case" and "patientive case" used above are descriptive but not standard. They are sometimes replaced by the terms "active" and "inactive". The names of the subtypes, "split-S" and "fluid-S", come from the designation of the single argument of intransitive verbs as "S". The names were first used by Robert M. W. Dixon in 1979. (†) = extinct language According to Castro Alves (2010), a split-S alignment can be safely