The injunctive mood is a

grammatical mood In linguistics, grammatical mood is a grammatical feature of verbs, used for signaling modality. That is, it is the use of verbal inflections that allow speakers to express their attitude toward what they are saying (for example, a statement ...

Sanskrit Sanskrit (; stem form ; nominal singular , ,) is a classical language belonging to the Indo-Aryan languages, Indo-Aryan branch of the Indo-European languages. It arose in northwest South Asia after its predecessor languages had Trans-cultural ...

that was characterized by secondary endings but no augment, and usually looked like an augmentless

aorist Aorist ( ; abbreviated ) verb forms usually express perfective aspect and refer to past events, similar to a preterite. Ancient Greek grammar had the aorist form, and the grammars of other Indo-European languages and languages influenced by the ...

or imperfect. It typically stood in a main clause and had a subjunctive or imperative meaning; for example, it could indicate intention, e.g. "Indra's heroic deeds will/shall I now declaim". It was obligatory for use in prohibitions, where it follows . In later

Classical Sanskrit Sanskrit (; stem form ; nominal singular , ,) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in northwest South Asia after its predecessor languages had diffused there from the northwest ...

, only the use after remained (there are no accents in Classical Sanskrit).

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

has words that are formally similar to the Sanskrit injunctive mood, consisting of

and imperfect forms lacking the augment. However, in this case there is no difference in meaning between these forms and the normal augmented forms. These are normally used in

Homer Homer (; , ; possibly born ) was an Ancient Greece, Ancient Greek poet who is credited as the author of the ''Iliad'' and the ''Odyssey'', two epic poems that are foundational works of ancient Greek literature. Despite doubts about his autho ...

and other

epic poetry In poetry, an epic is a lengthy narrative poem typically about the extraordinary deeds of extraordinary characters who, in dealings with gods or other superhuman forces, gave shape to the mortal universe for their descendants. With regard t ...

(see

Homeric Greek Homeric Greek is the form of the Greek language that was used in the ''Iliad'', ''Odyssey'', and ''Homeric Hymns''. It is a literary dialect of Ancient Greek consisting mainly of an archaic form of Ionic, with some Aeolic forms, a few from Ar ...

). It is generally assumed that the augment was originally a separate particle meaning something like "then", added to indicate the past time of a form that was once mostly aspectual, and neutral with respect to tense. Originally, its use appears to have been optional, added as necessary to clear up an otherwise ambiguous expression, similarly to time adverbs in Chinese. Gradually, it fused onto the verb form and became mandatory, but in the early stages of Greek and Sanskrit this change was not yet complete, and hence augmentless forms existed side-by-side with augmented forms. The modal semantics of the augmentless forms may then be a later development within Indo-Iranian or Indo-Aryan. It's also possible that the modal semantics developed in the parent language and later developments in Pre-Greek removed them and put back the basic meaning of the aorist and imperative, by analogy.

References

Sanskrit grammar Indo-European linguistics {{Grammatical moods Grammatical moods