A value of Aspect Property assigned to the designated element in the clause when the meaning selected for the clause is that which indicates that the situation spoken about has internal temporal structure, but the situation cannot be regarded as habitual (i.e. it cannot be regarded as a characteristic feature of a whole period). Hence, continuousness can be defined negatively as imperfectivity that is not habituality [Comrie 1976: 26-32], and it can be regarded as a sub-type of imperfectivity.
Typically, for an aspect value to be labelled as Continuous, the aspectual meaning has to minimally express continuousness, although it may additionally express other temporal, aspectual, or modal meanings, or actionality distinctions.
Continuous aspectual meaning can be further subdivided into two types: progressive meaning and nonprogressive meaning. These two aspectual meanings may or may not be grammaticalised as separate aspect values. [Kibort 2008c: 8]