A conditional clause preceded by εἴθε (eíthe) or εἰ γάρ (ei gár) "if only" is also occasionally used in Greek for making a wish.
However, ἄν (án) can sometimes be omitted, for example if the apodosis has an imperfect tense verb such as ἔδει (édei) "it was necessary" or ἐξῆν (exên) "it was possible".
[16] In the following examples, the protasis has the present subjunctive, and the apodosis has the future indicative: The apodosis can contain a present tense, if the verb is δεῖ (deî) "it is necessary": The negative used in a conditional clause is usually μή (mḗ): However, sometimes the negative οὐ (ou) is used, for example, when οὔ φημι (oú phēmi) has the force of a single word "deny":[24] In the following example, the aorist subjunctive is used in the protasis, to indicate that the action of capturing the hill must be done first before the enemy can be dislodged: The "less vivid" future (or "ideal") conditional describes a hypothetical situation in the future.
This is known as a "gnomic aorist":[38] The optative mood can similarly be used after εἰ (ei) "if" in general clauses of the type "if ever it used to happen".
[59] In the following example, ἐξεγένετο (exegéneto) is the aorist tense corresponding to the imperfect ἐξῆν (exên): Some other expressions also lack ἄν (án), for example:[61] A vivid future conditional clause using ἐάν (eán) with the subjunctive can be used with the meaning "in the hope that", "in case by chance", or "to see if perhaps", "on the off chance that".
In this case it has the same construction as a less vivid future condition:[69] An unattainable wish about the present or past is expressed using the imperfect or aorist indicative, preceded by εἴθε (eíthe) or εἰ γάρ (ei gár), that is, with the same construction as for an unreal present or past condition.
[71] The imperfect indicative is used for present time: The aorist indicative is used for an unattainable wish referring to past time: Sometimes the aorist tense of the verb ὀφείλω (opheílō) "I owe" is added:[74] Hence in the well-known opening of Euripides' play Medea: A common idiom in Ancient Greek is for the protasis of a conditional clause to be replaced by a relative clause.
[77] Such relative clauses are always indefinite, for example:[78] The main verbs in indirect statements are commonly changed to the infinitive, except when the quoted sentence is introduced by ὅτι (hóti) or ὡς (hōs).
[82] In indirect conditional clauses, in a historic context, ἐάν + subjunctive may optionally be changed to εἰ + optative.
The following table shows how the tenses of an original statement are changed to different tenses of the infinitive, participle, and optative when the speech is made indirect: In the four examples of indirect statement below, all the main verbs of the original speech have been changed to an infinitive.
The verb in the protasis, which would have been an imperfect indicative in the original speech, has been changed to a present participle using the genitive absolute construction.
The verb in the relative clause (στρατεὐομαι strateúomai "I am campaigning") is changed from present to imperfect indicative:[91] Indirect statements can also be made in Greek using the conjunction ὅτι (hóti) "that".
[100] The presence of ἄν (án) in the following sentence shows that the original question had a potential optative ("would you give?
[106] In Homer, in the protasis of a vivid future conditional, εἰ (ei) can be used on its own with the subjunctive, without κέ (ké) or ἄν (án), and without any difference in meaning.
In the following, both verbs are aorist subjunctive: In present general conditions, κέ or ἄν are often absent from the protasis.
[110] In the following example, the verb καταπέψῃ (katapépsēi) is aorist subjunctive, while ἔχει (ékhei) "he keeps" is present indicative: In the less vivid future conditional, κέ or ἄν can be added after εἰ, with no difference in meaning.
In the following, both verbs are aorist optative:[112] In Homer, the imperfect in unreal conditionals refers only to past time.