Conditional clauses in Ancient Greek are clauses which start with εἰ (ei) "if" or ἐάν (eān) "if (it may be)". ἐάν (eān) can be contracted to ἤν (ḗn) or ἄν (ā́n), with a long vowel. The "if"-clause of a conditional sentence is called the protasis, and the consequent or main clause is called the apodosis.
The negative particle in a conditional clause is usually μή (mḗ), making the conjunctions εἰ μή (ei mḗ) or ἐὰν μή (eàn mḗ) "unless", "if not". However, some conditions have οὐ (ou). The apodosis usually has οὐ (ou).
A conditional clause preceded by εἴθε (eíthe) or εἰ γάρ (ei gár) "if only" is also occasionally used in Greek for making a wish. The conjunction εἰ (ei) "if" also frequently introduces an indirect question.
Classification of conditional clauses
Conditional clauses are classified into a small number of different types, as shown on the table below.
Grammatically, there is no difference between a present general condition ("if ever it happens") and a vivid future ("if it happens"), both having ἐάν (eán) with the subjunctive. Similarly there is no difference between a past general condition ("if ever it happened") and a less vivid future condition ("if it were to happen"), both having εἰ (ei) with the optative. In this case, only the apodosis will distinguish which type of clause it is.
Those conditions which imagine a purely hypothetical situation (for example, "if I were to die", "if I was dead", "if I had died") usually have the particle ἄν (án) in the apodosis. 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".
If it is true
εἰ + present or perfect indicative
indicative or imperative
If it happens (in future)
εἰ + future indicative
If it happens (in future)
ἐάν + subjunctive
If ever it happens
ἐάν + subjunctive
If it was true
εἰ + imperfect or aorist indicative
If ever it used to happen
εἰ + optative
Less vivid future
If it were to happen
εἰ + optative
optative + ἄν
If it were true
εἰ + imperfect indicative
imperfect indicative + ἄν
If it had happened
εἰ + aorist indicative
aorist indicative + ἄν
Simple (open) conditions
A simple condition uses the indicative in the protasis. The apodosis can have an imperative:
ei dʼ, hōs légeis, sḕn thugatérʼ ékteinen patḗr, egṑ tí sʼ ēdíkēsʼ emós te súngonos?
"even if, as you say, our father killed your daughter, how did I or my brother wrong you?"
"Emotional" future conditions
In an open conditional the tense of the protasis can be future indicative. According to Smyth, this kind of vivid future conditional is used when the protasis expresses strong feeling: "the apodosis commonly conveys a threat, a warning, or an earnest appeal to the feelings". He refers to it as the "emotional future" conditional.
In the following, a present tense apodosis is combined with a future protasis:
"there is no food for the army, unless we capture the fort."
In the following poetic example, the protasis has a future indicative as before, but in the apodosis instead of a future, there is an aorist indicative:
ἀπωλόμην ἄρ᾽, εἴ με δὴ λείψεις, γύναι. (Euripides)
apōlómēn ár᾽, eí me dḕ leípseis, gúnai.
"I am undone if you leave me, wife!"
Vivid future conditions
A conditional clause referring to the future usually uses the conjunction ἐάν (eán), which can be shortened to ἤν or ἄν (ḗn, ā́n) "if (by chance)" followed by the subjunctive mood. (The second vowel of ἐάν (eán) is long, as appears from examples in Sophocles and Aristophanes.)
Conditional sentences of this kind are referred to by Smyth as the "more vivid" future conditions, and are very common. In the following examples, the protasis has the present subjunctive, and the apodosis has the future indicative:
"if we can first capture that (hill), the men threatening the road will not be able to remain."
Less vivid future conditions
The "less vivid" future (or "ideal") conditional describes a hypothetical situation in the future. There is often an implication that the speaker does not expect the situation to actually happen. The optative mood is used in both halves of the sentence, with the particleἄν (án) added before or after the verb in the apodosis.
The tense of the verb can be aorist (if it is an event) or present (if it describes a situation). The following three examples use the aorist optative:
In post-classical Greek, the optative mood gradually fell out of use. In the New Testament the potential optative with ἄν (án) occurs, but rarely (e.g. Acts 8:31); εἰ (ei) with the optative also sometimes occurs (e.g. 2 Peter 3:14).
Present general conditions
A present general condition uses the same grammatical construction (ἐάν with the subjunctive) as a vivid future condition, but is much less common. The present subjunctive is used when the actions of the two clauses are contemporaneous:
"whether (the hare) has been caught or not, (the huntsman) should make it clear (to his colleagues)."
Occasionally, the verb in the apodosis is an aorist tense, but with the sense of a present. This is known as a "gnomic aorist":
ἢν δέ τις τούτων τι παραβαίνῃ, ζημίαν αὐτοῖς ἐπέθεσαν. (Xenophon)
ḕn dé tis toútōn ti parabaínēi, zēmían autoîs epéthesan.
"if a man transgress anyone one of these laws, they always impose a penalty on him."
Past general conditions
The optative mood can similarly be used after εἰ (ei) "if" in general clauses of the type "if ever it used to happen". In the following examples the present optative is used in the protasis, and the imperfect indicative in the apodosis:
kaì oútʼ en tôi húdati tà hópla ên ékhein; ei dè mḗ, hḗrpazen ho potamós.
"and it was not possible to hold their weapons in the water, otherwise the river kept snatching them away."
Sometimes in the apodosis of a past general condition, the particle ἄνán is added to an imperfect or aorist indicative tense to express repeated past action. This is called the "iterative imperfect or aorist". The following example has the imperfect indicative with ἄνán:
εἰ δέ τις αὐτῷ περί του ἀντιλέγοι ... ἐπὶ τὴν ὑπόθεσιν ἐπανῆγεν ἂν πάντα τὸν λόγον. (Xenophon)
ei dé tis autôi perí tou antilégoi ... epì tḕn hupóthesin epanêgen àn pánta tòn lógon.
"if ever anyone opposed him on anything ... he would bring the whole subject back to the beginning"
The following uses the aorist indicative with ἄνán:
'if ever anyone seemed to him to be lagging behind, he would pick out the culprit and would beat him.'
Present unreal conditions
Unreal (counterfactual) conditions referring to present time are made with εἰ (ei) followed by the imperfect indicative in the protasis, and the imperfect indicative combined with the particle ἄν (án) in the apodosis:
"for who would have expected these things to happen?"
An imperfect tense in an unreal condition can refer to the past as well as the present, as in the following, where the verb ἠπιστάμην (ēpistámēn) is imperfect indicative. The verb in the apodosis, συνηκολούθησά (sunēkoloúthēsá), is aorist indicative:
"if I had not been toiling then, I would not now be rejoicing."
The particle ἄν (án) is occasionally omitted from an unreal condition, especially if the apodosis contains an imperfect tense verb of obligation or possibility, such as ἐξῆν (exên) "it was possible":
emè dʼ exên autôi, ei esōphrónei, mḕ sukophanteîn.
"it would have been possible for him, if he had been wise, not to accuse me falsely."
However, in other examples, where the emphasis is on the possibility or the necessity rather than the dependent infinitive, ἄν (án) is added. In the following example, ἐξεγένετο (exegéneto) is the aorist tense corresponding to the imperfect ἐξῆν (exên):
"listen to me too, in case the same things may still seem true to you."
In a historic context, this type of clause becomes a less vivid future, using εἰ (ei) or εἰ πως (ei pōs) "if by chance" with the optative mood. In the first example below, πείσειαν (peíseian) "they might persuade" is aorist optative:
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. The imperfect indicative is used for present time:
A common idiom in Ancient Greek is for the protasis of a conditional clause to be replaced by a relative clause. (For example, "whoever saw it would be amazed" = "if anyone saw it, they would be amazed.") Such sentences are known as "conditional relative clauses", and they follow the same grammar as ordinary conditionals. Such relative clauses are always indefinite, for example:
"your children, as many as were here (i.e. if any had been here), would have been abused by these men."
Conditional clauses in indirect speech
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). Subordinate clause verbs, and main verbs after ὅτι (hóti) or ὡς (hōs), may optionally be changed to the optative mood, but only when the context is historic. In some circumstances a verb is changed to a participle, and sometimes a present indicative becomes imperfect tense.
In indirect conditional clauses, in a historic context, ἐάν + subjunctive may optionally be changed to εἰ + optative. However, an imperfect or aorist indicative in the protasis of an unreal conditional sentence is not changed to the optative. In the apodosis of an ideal or unreal conditional, ἄν is retained when the verb is changed to an infinitive or participle.
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:
Present or imperfect
Perfect or pluperfect
Indirect statements with the infinitive
In the four examples of indirect statement below, all the main verbs of the original speech have been changed to an infinitive.
The first example is an indirect present tense open conditional. The present infinitive ἐλευθεροῦν (eleutheroûn) represents a present indicative (ἐλευθεροῖςeleutheroîs "you are freeing") in the original speech. The present indicative verb of the protasis ("you are killing") is changed to the imperfect indicative, as if the writer were stating a fact rather than quoting a speech:
élegon ou kalôs tḕn Helláda eleutheroûn autón, ei ándras diéphtheiren.
"they said that he was not freeing Greece in a good way, if he was killing men."
The following example is an indirect emotional future conditional. The two main verbs ("there is" and "it will be") have been changed to the present and future infinitive respectively. The future indicative in the protasis ("will capture in advance") has been changed into the future optative mood:
"he said that there was a hill-top which, unless someone captured it first, it was going to be impossible to get past."
The following is an unreal past conditional. 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 aorist tense main verb has been changed into the aorist infinitive; the particle ἄν (án) is retained, but has been placed after the participle:
"do you think that, if someone had told them, they would have believed it?" (εἴ τις ἔλεγεν, ἐπίστευσαν ἄν;)
The following is a vivid future conditional in a historic context. The main verb "I will not stop" is changed into the future infinitive. ἐάν (eán) "if" and πρὶν ἄν (prìn án) "before" with the aorist subjunctive have been changed into εἰ (ei) and πρίν (prín) with the aorist optative. The verb in the relative clause (στρατεὐομαιstrateúomai "I am campaigning") is changed from present to imperfect indicative:
huposkhómenos autoîs, ei kalôs katapráxeien ephʼ hà estrateúeto, mḕ prósthen paúsesthai prìn autoùs katagágoi oíkade.
"promising them that if he accomplished what he was campaigning for, he would not stop until he brought them back home." (εἰ καλῶς καταπράξομαι ἐφʼ ἅ στρατεὐομαι, οὐ πρόσθεν παύσομαι πρὶν ἂν ὑμᾶς καταγάγω οἴκαδε.)
Indirect statements with ὅτι
Indirect statements can also be made in Greek using the conjunction ὅτι (hóti) "that". If the context is past, the verbs may optionally be changed to the optative mood.
In the following example, the main verb ἐπιθήσοιεν (epithḗsoien) has been changed to the future optative, but the future indicative in the protasis has not been changed to the optative:
apelogoûnto hōs ouk án pote hoútō môroi êsan ei eídesan.
"they pleaded that they would never have been so foolish if they had known."
An indirect question is often introduced by εἰ (ei) "if", even though the original question does not contain a conditional clause. In a historic context, the main verb may be changed to the optative mood, as in the first example below. In this example, the 2nd person present indicative βούλει; (boúlei?) "are you willing?" has been changed to the 3rd person present optative. The aorist participle λαβών (labṓn) "having received" possibly stands for a vivid future ("if you receive") or less vivid future protasis ("if you were to receive"):
ei oûn ti boúlontai saphès légein, pémpsai ándras hōs autón.
"(the letter said that) if therefore they wished to say something clearly, they should send some men to him."
In the above sentence, although the context is historic, the writer has chosen not to use the optative but the more vivid indicative mood with the verb βούλονται "they wish". This retention of the vivid mood is typical of Thucydides's style.
Conditional clauses in Homer
There are some differences between Homeric conditionals and those in classical Greek. As well as εἰ (ei) "if", Homer also uses the Aeolic dialect form αἰ (ai). As well as the particle ἄν (án), Homer also uses κέ (ké) or κέν (kén). κέ(ν) (ké(n)) is more frequent than ἄν (án), especially in affirmative sentences.
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, the protasis has the aorist subjunctive, while the apodosis has the future indicative:
εἴ περ γάρ σε κατακτάνῃ, οὔ σε ... κλαύσομαι. (Iliad)
eí per gár se kataktánēi, oú se ... klaúsomai.
"for if he kills you, I will not weep for you."
Another construction not found in classical Greek is to use the subjunctive with κέ (ké) in both clauses. In the following, both verbs are aorist subjunctive:
"but if he does not give her up, I will seize her myself."
In present general conditions, κέ or ἄν are often absent from the protasis. In the following example, the verb καταπέψῃ (katapépsēi) is aorist subjunctive, while ἔχει (ékhei) "he keeps" is present indicative:
ou mèn gár ti kakṓteron állo páthoimi, oudʼ eí ken toû patròs apophthiménoio puthoímēn.
"for I could not suffer anything worse, not even if I found out that my father had died"
In Homer, the imperfect in unreal conditionals refers only to past time. In a present unreal conditional, the protasis may have the optative in both halves, although this is very rare. In a past unreal conditional the protasis has either an imperfect or an aorist indicative, and in the apodosis either an imperfect or aorist indicative with ἄν (án) or κέ (ké), or an aorist or present optative with κέ (ké). In the following example, νόησε is aorist indicative, and ἀπολοιτο is aorist optative: