Original sentence: Greek verb morphology is structured around a basic 2-by-2 contrast of two aspects (imperfective and perfective), and two tenses (past and present/non-past).Of the four possible combinations, only three can be used in indicative function: the (imperfective) present, the  imperfect (i
Edited sentence: Greek verb morphology is structured around a basic 2-by-2 contrast of two aspects, namely imperfective and perfective, and two tenses, namely past and non-past (or present).Of the four possible combinations, only three can be used in indicative function: the present (imperfective non-past), the  imperfect (i