This article builds on my Ph.D thesis (Trondhjem 2007) and shows that unlike traditional Europian descriptions of tense, where tense is conveyed by the inflection, tense is marked by optional derivational affixes in West Greenlandic (WG). In this language time is marked in three different ways, first by conjunction, indicating simultaneous and sequential situations, secondly by aspectual affixes, and thirdly by tense affixes. The meanings of the past time markers -sima, -nikuu and -reer have developed from aspectual meanings to also include tense meanings among others. This article shows a number of rules for the meaning of past time.