Optative (Ancient Greek)
The optative mood, from Ancient Greek (énklisis) euktikḗ "(inflection) for wishing" and Latin optātīvus (modus) "(way) of wishing", is a grammatical mood of the Ancient Greek verb, named for its use as a way to express wishes. It is also used to express potentiality and to replace other moods in dependent clauses under past-tense main verbs.
The optative of wish or volitive optative expresses wishes: "If only..." or "Would that...". It is sometimes preceded by εἴθε or εἰ γάρ (eíthe, ei gár).
The optative in the future less vivid conditional sentence is similar to the potential optative.
The optative mood is used in a subordinate clause that is governed by a past tense verb (secondary sequence).
In reported speech, the indicative in a direct quotation is replaced by the optative in an indirect quotation when the verb of saying is in a past tense (“said”). The present optative stands for both the present and the imperfect indicative, and the perfect optative stands for both the perfect and the pluperfect. The future optative stands for the future, and is only used in this construction.
Koine and gradual extinction
Later, as Koine Greek emerged following the conquests of Alexander the Great c. 333 BC, the use of the optative began to wane among many Greek writers. In the New Testament, the optative is primarily used in certain fixed expressions such as μὴ γένοιτο (mḕ génoito; "absolutely not!" or literally "may it not be!", e.g. Romans 7:7). See in particular O'Sullivan, Neil, '"It would be time to discuss the optatives," Understanding the Syntax of the Optative from Protagoras to Planudes', Antichthon 45, 2011, 77-112.
First person singular ending
Gordon M. Messing explains that in dealing with the endings of the optative mood, Herbert Weir Smyth merely noted without comment that the first person singular ending except after -ιη- was -μι, despite his previous statement that the optative usually has the endings of the secondary tenses of the indicative. The anomaly of the usual ending -μι has now been resolved with the discovery of Arcadian present optative first singular έξελαύνοια, which shows the original secondary ending previously assumed but hitherto unattested.