"...It is commonly assumed that the Latin tense divisions of past, present and future are inevitable.  Yet one frequently meets languages which do not make this neat threefold distinction.  In some languages, it is more important to express the duration of an action - whether it is a single act or a continuig process - than to locate the action in time." —from Jean Aitchison, Teach Yourself Linguistics, Teach Yourself, 2003, p. 7