stylistic:style_transfer, information:classification, stylistic:tone, linguistic:voice_change
Use of the tense-aspect forms

Jagersma systematizes the use of the tense-aspect forms in the following patterns:

In addition, different moods often require either a ḫamṭu or a marû stem and either a ḫamṭu or a marû agreement pattern depending on various conditions, as specified in the relevant sections above and below.

In more general terms, modern scholars usually state that the difference between the two forms is primarily one of aspect: ḫamṭu expresses perfective aspect, i.e. a completed action, or sometimes possibly punctual aspect, whereas marû expresses imperfective aspect, i.e. a non-completed action, or sometimes possibly durative aspect. In contrast, the time at which the action takes place or at which it is completed or non-completed is not specified and may be either past, present or future. This contrasts with the earlier view, prevalent in the first half of the 20th century, according to which the difference was one of tense: ḫamṭu was thought to express the past (preterite) tense, and marû was considered to express present- future tense, while the use of marû with past-tense reference was viewed as a stylistic device (cf. the so-called historical present use in other languages). Indeed it has been pointed out that a translation of ḫamṭu with past tense and marû with present or future tense does work well most of the time; this may correspond to the cases in which the action was viewed by Sumerian speakers as completed or non-completed with respect to the present moment.