Positive conjunctions

The usual conjunction in a conditional clause is sī, for which see the examples below.

Negative conditions

When the conditional clause is negative, there are various possibilities: nisi 'if not', 'unless', sī ... nōn 'if not', nī 'were it not that' and sī minus 'otherwise'.

Present or past

A present open conditional normally has the indicative in both halves. Various tenses are possible, but the present or perfect are common:

si iam melius valēs, vehementer gaudeō (Cicero)^[44]

'if you are in better health now, I am very glad'

sī peccāvī, īnsciēns fēcī (Terence)^[45]

'if I did wrong, I did so unwittingly'

sī tū oblītus es, at dī meminērunt, meminit Fidēs (Catullus)^[46]

'even if you have forgotten, yet the gods remember; Faithfulness remembers'

The following combines an imperfect tense in the protasis and future in the apodosis:^[47]

sī ille exitum nōn reperiēbat, quis nunc reperiet? (Cicero)^[48]

'if he was not able to find any way out, who will find one now?'

A conditional clause is often found after quid mīrum 'what is surprising?'

quid mīrum igitur in senibus, sī īnfirmī sunt aliquandō? (Cicero)^[49]

'why is it surprising, therefore, if old men are sometimes ill?'

Usually the verb of the apodosis is also indicative, but other moods are possible, such as the imperative below:

"dēsilite", inquit, "mīlitēs, nisi vultis aquilam hostibus prōdere" (Caesar)^[50]

'"jump down, soldiers," he said, "unless you wish to betray the eagle to the enemies"'

Future

In a future conditional, the protasis usually has one of the future tenses, where English has the simple present. In the following, the simple future tense is used:

sī enim erit bellum, cum Pompeiō esse cōnstituī (Cicero)^[51]

'if there is (lit. will be) a war, I have decided to be with Pompey'

experiar et dīcam, sī poterō, plānius (Cicero)^[52]

'I shall try and explain more clearly, if I can (lit. if I will be able)'

Often, however, a future conditional uses the future perfect indicative, to refer to an event that must take place first before the consequence happens:

haec sī attulerīs, cēnābis bene (Catullus)

'if you bring (lit. will have brought) these things, you will dine well'

egō ad tē, sī quid audierō citius, scrībam. (Cicero)^[53]

'if I hear (lit. will have heard) anything sooner, I will write to you'

egō sī ūllō modō potuerō, vel nocturnīs itineribus experiar ut tē videam (Cicero)^[54]

'if I can (lit. will have been able) in any way, even if it means travelling at night, I will try to see you'

ferrum in manū est; moriēre, sī ēmīserīs vōcem (Livy)^[55]

'there is a sword in my hand; you will die, if you utter (lit. will have uttered) a word!'

Sometimes both halves of the conditional can have the future perfect tense, though this is rare:^[56]

sī dīxerō mendācium, solēns meō mōre fēcerō (Plautus)^[57]

'if I do tell a lie, I will have done it as I usually do, according to my custom'

If the apodosis of a future conditional is a command, the future imperative (ending in -tō) is used, rather than the present imperative:

tū etiam sī quod scrībās nōn habēbis, scrībitō tamen (Cicero)^[58]

'even if you have nothing to write about, write all the same'

The use of the present subjunctive sī possim 'if perhaps I can' in the following example adds uncertainty:

'trānsīre Tiberim' inquit, 'patrēs, et intrāre, sī possim, castra hostium volō' (Livy)^[59]

'"I want to cross the Tiber," he said, "senators, and enter the enemies' camp, if perhaps I can"'

Although the future tense is usual in a protasis referring to the future, sometimes, as in English, in colloquial Latin a present tense is used:^[47]

sī illum relinquō, eius vītae timeō (Terence)^[60]

'if I abandon him, I fear for his life'

With the indicative

With general or iterative conditions, in writers of the classical period, it was usual to use the indicative mood, as in the following examples:

sī quandō in puerīs ante alter dēns nāscitur quam prior excidat, is quī cadere dēbuit ēvellendus est (Celsus)^[61]

'if ever in children a second tooth appears before the earlier one has fallen out, the one which ought to have fallen out must be uprooted'

Sometimes, just as with iterative temporal clauses, a perfect indicative in the protasis is followed by a present indicative in the main clause:^[62]

sī pēs condoluit, sī dēns, ferre nōn possumus (Cicero)^[63]

'if ever a foot or a tooth has begun to ache, we can't bear it'

In a past context, this becomes sī with the pluperfect indicative:

sī quandō nostrī ferreīs manibus iniectīs nāvem religāverant, undique suīs labōrantibus succurrēbant (Caesar)^[64]

'if ever our men by throwing in iron hooks had tied up a ship, the enemy would come running from all sides to help their struggling comrades'

sī ab persequendō hostēs dēterrēre nequīverant, disiectōs circumveniēbant (Sallust)^[65]

'if ever they had been unable to deter the enemy from pursuing, they would surround them when they were scattered'

sī tribūnī, sī legiō industriam innocentiamque adprobaverant, retinēbat ōrdinem (Tacitus)^[66]

'if the tribunes or legion approved of (a centurion's) industry and innocence, he would retain his rank'

With the subjunctive

In later writers (but still only rarely in Cicero or Caesar) a protasis with iterative meaning could sometimes use the subjunctive mood:^[67]

'chommoda' dīcēbat, sī quandō 'commoda' vellet dīcere (Catullus)^[68]

'he used to say "chommoda" if ever he wanted to say "commoda"'

quōrum sī quis ā dominō prehenderētur, cōnsēnsū mīlitum ēripiēbātur (Caesar)^[69]

'if ever any of these slaves was seized by his master, he would be rescued by a concerted effort of the soldiers'

2nd person singular generalisation

When a generalisation uses the 2nd person singular in a condition, meaning 'one' or 'anyone', the verb is usually in the subjunctive mood even in classical writers:^[70]

memoria minuitur, nisi eam exerceās (Cicero)^[71]

'memory gets weaker, if you don't exercise it'

standum est in lectō, sī quid dē summō petās (Plautus)^[72]

'you need to stand on the bed if you want to get something from on top'

The following similarly uses the perfect subjunctive with the 2nd person:

nūlla est excūsātiō peccātī, sī amīcī causā peccāverīs (Cicero)^[73]

'it is no excuse for doing wrong if you have done wrong for the sake of a friend'

The subjunctive is also used in the apodosis of a generalisation if it has a 2nd person singular verb:^[74]

sī nōn est, nōlīs esse neque dēsīderēs (Plautus)^[75]

'if there isn't one, you don't want there to be one and you don't miss it'

Ideal conditions (future)

Ideal conditions^[76] (also known as 'less vivid future conditions'^[77] or 'Type II conditions'^[78]) are those in which the speaker supposes a situation or an event which might occur in future, at least in the imagination. There is generally an assumption on the speaker's part that the event is not going to take place.

Past ideal conditionals

An ideal condition can occur in a past context also, in which case it uses the imperfect subjunctive.^[91][92] In the following, the apodosis has the imperfect subjunctive:

Caesar sī peteret... nōn quicquam prōficeret (Horace)^[93]

'even supposing Caesar himself were to have asked him (to sing), it wouldn't have done any good.'

at tum sī dīcerem, nōn audīrer (Cicero)^[94]

'but if I had tried to speak then, I would not have been heard.'

metuēns nē sī cōnsulum iniussū īret, forte dēprehēnsus ā custōdibus Rōmānīs retraherētur, senātum adit (Livy)^[95]

'fearing that if he were to go without the permission of the consuls, he might be caught and dragged back by the Roman guards, he approached the senate'

In the following, the verb in the apodosis is imperfect indicative:

neque mūnītiōnēs Caesaris prohibēre poterat, nisī proeliō dēcertāre vellet (Caesar)^[96]

'nor was there any way he was able to prevent Caesar's fortifications, unless he wished to fight it out with a battle'

sī lūce palam īrētur, hostis praeventūrus erat (Livy)^[97]

'if they went openly in daylight, the enemy was likely to get there first.'

Although conditionals of this kind use sī with the imperfect subjunctive in the same way as an unreal conditional, the meaning is different. In an unreal conditional, the imperfect subjunctive refers to a situation contrary to fact at the present time or at the time of the story, while in a past ideal conditional, the imperfect subjunctive refers prospectively to a situation that might have occurred at a later time than the time of the narrative.

Present unreal

In an unreal or counterfactual conditional sentence the imperfect subjunctive describes a situation contrary to fact in the present and what would follow if that situation were true. The apodosis also usually has the same tense:

ego sī somnum capere possem, tam longīs tē epistulīs nōn obtunderem (Cicero)

'if I could sleep, I wouldn't be bothering you with such long letters'

scrīberem ad tē dē hōc plūra, sī Rōmae essēs (Cicero)^[98]

'I would write more to you about this if you were in Rome'

quod egō sī verbō adsequī possem, istōs ipsōs ēicerem quī haec loquuntur (Cicero)^[99]

'if I were able to achieve this (i.e. the banishment of Catiline's friends) with a word, I would be banishing those men themselves who are saying this'

Woodcock notes that in early Latin such as Plautus, the present subjunctive rather than the imperfect is often used to represent a present-time counterfactual condition:^[100]

haud rogem tē, sī sciam (Plautus)^[101]

'I would not be asking you, if I knew.'

tū sī hīc sīs, aliter sentiās (Terence)^[102]

'if you were in my place, you would think differently'

In early Latin there is thus a blurring of the distinction between the ideal and the unreal conditional.^[103]

Past unreal

The pluperfect subjunctive, ending in -(i)ssem, represents an event contrary to fact in the past. The same tense is usually used both in the protasis and the apodosis:

sī Rōmae fuissem, tē vīdissem cōramque grātiās ēgissem (Cicero)^[104]

'if I had been in Rome, I would have seen you and thanked you in person'

sī occīdisset, rēctē fēcisset: sed nōn occīdit (Quintilian)^[105]

'if he had killed him, he would have done so rightly; but he did not kill him'

vōs agitāte fugam: mē sī caelicolae voluissent dūcere vītam, hās mihi servāssent sēdēs (Virgil)^[106]

'you flee, if you wish: but as for me, if the gods had wanted me to prolong my life, they would have saved this home for me'

omnium cōnsēnsū capāx imperiī nisī imperāsset (Tacitus)^[107]

'by everyone's consent, (Galba would have been seen as) capable of being Emperor, had he never ruled'

When the verb in apodosis is passive, in some authors the imperfect subjunctive esset can be replaced by foret to give a potential meaning to the pluperfect subjunctive:

dēlētusque exercitus foret nī fugientēs silvae texissent (Livy)^[108]

'and the army would have been annihilated if the woods hadn't provided cover for those who were fleeing'

obsessaque urbs foret, nī Horātius cōnsul esset revocātus (Livy)^[109]

'and the city would have been besieged, if the consul Horatius had not been recalled.'

In other authors, however, the same meaning is expressed using a perfect participle + esset:

quod nisi nox proelium dirēmisset, tōtā classe hostium Caesar potītus esset ([Caesar])^[110]

'but if night hadn't interrupted the battle, Caesar would have gained control of the whole enemy fleet'

Sometimes a pluperfect subjunctive is followed by an imperfect or vice versa:

ergō ego nisi peperissem, Rōma nōn oppugnārētur; nisi fīlium habērem, lībera in līberā patriā mortua essem (Livy)^[111]

'therefore if I had not given birth, Rome would not now be being attacked; if I did not have a son, I would have died a free woman in a free country'

sī Pergama dextrā dēfendī possent, etiam hāc dēfēnsa fuissent (Virgil)^[112]

'if Troy could be defended by anyone's right hand, it would have been defended before now even by this one'

Sometimes an imperfect subjunctive refers to the past rather than the present, and represents a hypothetical situation prevailing at the time of the event described in the apodosis:^[113]

neque enim tam facile opēs Carthāginis tantae concidissent nisi illud receptāculum classibus nostrīs patēret (Cicero)^[114]

'for the great wealth of Carthage would not have collapsed so easily, if that refuge had not been available to our fleets at the time'

hic sī mentis esset suae, ausus esset ēdūcere exercitum? (Cicero)^[115]

'if this man had been in his right mind, would he have dared to lead out an army?'

Sometimes in poetry, an unreal conditional uses the present or perfect subjunctive as if it were an ideal conditional:^[116]

nī mea cūra resistat, iam flammae tulerint (Virgil)^[117]

'had my care not stood in the way, flames would already have carried them off.'

nī docta comes admoneat ... inruat, et frūstrā ferrō dīverberet umbrās (Virgil)^[118]

'and if his learned companion had not warned him, he would have rushed in and vainly beaten away the shadows with his sword'

An imperfect subjunctive can sometimes be used in poetry with a similar meaning:

quīn prōtinus omnia perlegerent oculīs, nī iam praemissus Achātes adforet (Virgil)^[119]

'indeed they would have continued examining everything carefully with their eyes, had it not been that Achates, who had been sent ahead, was now present'

Indicative in the apodosis

Although most unreal conditionals have the subjunctive in the apodosis, it is also possible, just as with ideal conditions, sometimes to use the indicative, especially if the verb is one of possibility or obligation:^[120][121]

neque sustinērī poterant, nī extraōrdināriae cohortēs sē obiēcissent (Livy)^[122]

'and they could not have been withstood, if the reserved cohorts had not thrown themselves in the way'

nisi fēlicitās in sōcordiam vertisset, exuere iugam potuēre (Tacitus)^[123]

'if their success hadn't turned into laziness, they might well have thrown off the yoke'

Antōnī gladiōs potuit contemnere, sī sīc omnia dīxisset (Juvenal)^[124]

'(Cicero) would have been able to despise Antony's swords, if he had said everything as badly as this'

sī ūnum diem morātī essētis, moriendum omnibus fuit (Livy)^[125]

'if you had delayed for a single day, you must certainly have all died.'

quod sī ita putāsset, certē optābilius Milōnī fuit dare iugulum P. Clōdiō (Cicero)^[126]

'but if he had thought like this, it would certainly have been preferable for Milo to offer his throat to Publius Clodius'

The imperfect indicative is used for actions that were interrupted. The protasis is usually negative:

lābēbar longius, nisi mē retinuissem (Cicero)^[127]

'I was about to fall further into error, if I had not held myself back'

in amplexūs occurrentis fīliae ruēbat, nisi interiectī lictōres utrīsque obstitissent (Tacitus)^[128]

'he was rushing into the embrace of his daughter who was running towards him, (and they would have hugged) if the bodyguards had not intervened and stood in the way of them both'

Caecīna dēlāpsus circumveniēbātur, nī prīma legiō sēsē opposuisset (Tacitus)^[129]

'Caecina had fallen and was about to be surrounded, if the first legion hadn't put themselves in the way'

The perfect indicative with paene 'almost' indicates an event that nearly took place:

pōns sublicius iter paene hostibus dedit, nī ūnus vir fuisset, Horātius Cocles. (Livy)^[39]

'the wooden bridge almost gave the enemy a means of entry, had it not been for one man, Horatius Cocles.'

The pluperfect indicative is sometimes used for events that looked almost certain to happen:

nisi Latīnī arma sūmpsissent, captī et dēletī erāmus (Livy)^[130]

'if the Latins had not taken up arms, we would certainly have been captured and wiped out.'

perāctum erat bellum, sī Pompeium Brundisiī opprimere potuisset (Florus)^[131]

'the war would have been over immediately, if he had managed to crush Pompey in Brundisium.'

In later, post-classical Latin, it became regular for the indicative to be used in the apodosis of an unreal conditional, as in this example from Gregory of Tours (6th century A.D.):^[132]

sī fās fuisset, angelum dē caelō ēvocāveram (Gregory of Tours)^[133]

'if it had been allowable, I would have called an angel from heaven'

Indirect present and future conditions

Subordinate clauses in indirect speech usually use the subjunctive mood. However, if the introductory verb is 1st or 2nd person, the indicative is sometimes retained in a conditional clause, as in the following example:^[154]

spērō, sī absolūtus erit, coniūnctiōrem illum nōbīs fore in ratiōne petītiōnis (Cicero)^[155]

'I hope that if (Catiline) is acquitted, he will work more closely with me in my election campaign'

Otherwise the verb in the protasis becomes subjunctive, as in the following:

sī adīre non possit, monet ut trāgulam cum epistolā ad āmentum dēligatā intrā munītiōnem castrōrum abiciat (Caesar)^[156]

'he advises him that, if he can't approach, he should throw a javelin inside the walls of the camp with the letter attached to the strap'

sī pāce ūtī velint, inīquum esse dē stīpendiō recūsāre (Caesar)^[157]

'(he said that) if they wished for peace, it was unfair to refuse to pay tribute'

The verbs in the above sentences are present subjunctive, despite the historic context, by a process called repraesentātiō, which makes the situation more vivid.^[158]

If the verb in an apodosis is a future perfect tense in direct speech, it cannot be expressed using an active verb, but it is possible to use or deponent or passive perfect participle with fore:^[159]

hoc possum dīcere, mē satis adeptum fore, sī nūllum in mē perīculum redundārit (Cicero)^[160]

'I can say this, that I will have achieved enough, if no danger redounds on me'

When the context is past, a future perfect tense in the protasis usually becomes a pluperfect subjunctive:

futūrum esse, nisī prōvīsum esset, ut Rōma caperētur (Cicero)^[161]

'(the voice said) that, unless some precaution was taken, Rome would be captured'

monuit Crassum quid ēventūrum esset, nisi cāvisset (Cicero)^[162]

'he warned Crassus what was likely to happen, if he wasn't careful'

templum Iovī Statōri vovet, sī cōnstitisset ā fugā Rōmāna aciēs (Livy)^[163]

'(Regulus) vowed a temple to Jupiter the Stayer, if the Roman battle-line stopped fleeing'

prōnūntiat Gracchus esse nihil quod dē lībertāte spērārent, nisi eō diē fūsī fugātīque hostēs essent (Livy)^[164]

'Gracchus proclaimed that they had no hope at all of liberty unless the enemy were routed and put to flight on that day'

However, again by repraesentātiō, the perfect subjunctive is used in the protasis below even in a past context, as if it followed a present tense verb:

haec sī Ariovistō nūntiāta sint, nōn dubitāre quīn dē omnibus supplicium sūmat (Caesar)^[165]

'they said that if these things were reported to Ariovistus, they did not doubt that he would punish them all'

In the following sentence, instead of a pluperfect subjunctive, the imperfect subjunctive restituerētur is used with a prospective or future meaning:^[166]

nec, sī illa restituerētur, dubitāvī quīn mē sēcum redūceret (Cicero)^[167]

'and I didn't doubt that, if the republican government were restored, it would bring me back with it'

The subjunctive foret (derived from the future infinitive fore), can sometimes be used in the protasis instead of esset to refer to a future situation in indirect speech (see Latin tenses#Foret):

usūrum sē eōrum operā sī bellum cum Veientibus foret (Livy)^[168]

'(he said that) he would use their help if ever one day there was a war with the people of Veii'

sī summus foret, futūrum brevem (Cicero)^[169]

'(he was confident) that even if (the pain) were going to be very great, it would be brief'

Combined with a perfect or deponent participle, foret can stand in a protasis for a future perfect tense of direct speech:

cōnsulātum petēbat spērāns, sī dēsignātus foret, facile sē ex voluntāte Antōniō ūsūrum (Sallust)^[170]

'he was seeking the consulship, hoping that if he should be elected he would easily manage Antony according to his pleasure'

timor inde patrēs incessit nē, sī dīmissus exercitus foret, rūrsus coetūs occultī coniūratiōnēsque fīerent (Livy)^[171]

'the senators then became afraid that, if the army was dismissed, once again secret gatherings and conspiracies might take place'

quasi polluī cōnsulātum crēdēbant, sī eum quamvīs ēgregius homō novus adeptus foret (Sallust)^[172]

'they believed that the consulate would be almost polluted, if a new man, however, talented, were to have obtained it'

Indirect ideal conditions

Since in indirect speech the subjunctive is usually used in a subordinate clause, the distinction between the ideal conditional and the simple future conditional disappears.^[173] In the following examples, only the context indicates that the conditional is ideal:

ait sē sī ūrātur 'quam hoc suāve!' dictūrum (Cicero)^[174]

'he says that if he were to be being burnt, he would say "how pleasant this is!"'

The perfect subjunctive can also be used if the context is present:

quem adhūc nōs quidem vīdimus nēminem; sed philosophōrum sententiīs, quālis hic futūrus sit, sī modō aliquandō fuerit, expōnitur (Cicero)^[175]

'we ourselves have never seen such a (perfectly wise) man; but it is explained in the opinions of philosophers what such a person would be like, if one were ever to exist'

As mentioned above, the perfect participle with fore represents a future perfect passive in the main clause:

metum sī quī sūstulisset, omnem vītae dīligentiam sublātam fore (Cicero)^[176]

'(the philosophers say that) if someone removed fear, all carefulness of living would have been removed too'

Indirect unreal conditions (present)

If a conditional clause in indirect speech describes a present situation contrary to fact, the verb in the apodosis is the periphrastic perfect infinitive, consisting of a future participle + fuisse (e.g. factūrum fuisse).^[177] The imperfect subjunctive in the protasis remains unchanged, even after a primary tense verb:

quid censēs? sī ratiō esset in bēluīs, nōn suō quāsque generī plūrimum tribūtūrās fuisse? (Cicero)^[178]

'what do you think? do you not think that if reason existed in wild beasts, each kind would not attribute most to its own kind?'

fatentur sē virtūtis causā, nisi ea voluptātem faceret, nē manum quidem versūrōs fuisse (Cicero)^[179]

'they confess that they would not even lift a hand for the sake of virtue, unless virtue itself gave pleasure'

an tū cēnsēs ūllam anum tam dēlīram futūram fuisse ut somniīs crēderet, nisī ista cāsū nōn nunquam forte temerē concurrerent? (Cicero)^[180]

'do you think any old woman would be so crazy as to believe in dreams if those dreams didn't come true by chance sometimes?'

quid putāmus passūrum fuisse sī vīveret? – nobīscum cēnāret! (Pliny)^[181]

'what do we think would be happening to him if he were alive?' – 'he would be dining with us!'

In the following, a present unreal situation follows from an unreal past condition:

stīpendium scītōte pependisse sociōs vestrōs Gallīs, et nunc fuisse pēnsūrōs, sī ā mē foret cessātum (Livy)^[182]

'be aware that your allies used to pay tribute to the Gauls, and they would still be paying now, if my efforts had been slackened'

If the apodosis is an indirect question, the future participle is combined with the perfect subjunctive fuerit instead of the perfect infinitive fuisse:^[183]

cōgitā quantum additūrus celeritātī fuerīs, sī ā tergō hostis īnstāret! (Seneca)^[184]

'think how much extra speed you would put on, if an enemy were pursuing you from behind!'

Indirect unreal conditions (past)

In an indirect past unreal conditional, the apodosis is also often expressed using the future participle plus fuisse, exactly as a present unreal conditional:^[185]

nōn vidētur mentītūrus fuisse, nisī dēspērāsset (Quintilian)^[186]

'it is unlikely that he would have told a lie unless he had been desperate'

hoc tamen nūntiā, melius mē moritūram fuisse sī nōn in fūnere meō nūpsissem (Livy)^[187]

'but take this message to him, that I would have died better if I had not married on the day of my funeral!'

facturum enim se fuisse dixit ut duorum patriciorum nomina reciperet, si alium quam se consulem fieri uideret (Livy)^[188]

'for he said that he would have agreed to accept the names of two patricians, if he could see anyone other than himself becoming consul'

When the indirect speech is an indirect question, or a quīn clause, rather than an indirect statement, the construction in the apodosis is the same, except that the perfect infinitive fuisse is replaced by the perfect subjunctive fuerit:

dīc agedum, Appī Claudī, quidnam factūrus fuerīs, sī eō tempore cēnsor fuissēs? (Livy)^[189]

'tell us, Appius Claudius, what you would have done if you had been censor at that time?'

When the verb is passive, futūrum fuisse ut can occasionally be used.^[190] However, this is very rare, and only two instances have been noted:^[191]

nisi eō ipsō tempore quīdam nūntiī dē Caesaris victōriā essent allātī, exīstimābant plērīque futūrum fuisse utī āmitterētur (Caesar)^[192]

'if at that very moment certain reports had not arrived bringing news of Caesar's victory, most people reckoned that the town would have been lost'

Another way of expressing a passive verb in the apodosis of an unreal conditional in indirect speech is to use the perfect infinitive of possum combined with a present passive infinitive; that is, to write 'could have been done' instead of 'would have been done', since the two are close in meaning:^[183]

at plerīque exīstimant, sī ācrius īnsequī voluisset, bellum eō diē potuisse fīnīrī (Caesar)^[193]

'but most people think that if he had been prepared to follow up the pursuit more vigorously, the war could have been finished on that day'

Similarly in an indirect question, the perfect subjunctive potuerit with the present infinitive can be used:

quaeris quid potuerit amplius adsequī Plancius, sī Cn. Scīpionis fuisset fīlius (Cicero)^[194]

'you ask what more Plancius could/would have achieved, if he had been the son of Gnaeus Scipio'

Another possibility, when the main verb in a quīn-clause is passive, is for the tense to be unchanged from direct speech. Thus in the following, the pluperfect subjunctive is retained:^[195]

id ille sī repudiāsset, dubitātis quīn eī vīs esset allāta? (Cicero)^[196]

'if he had rejected that, do you doubt that violence would have been done to him?'

Even after a historic introductory verb, the perfect subjunctive is usually still retained in a quīn clause (contrary to the usual sequence of tenses rule):^[195]

nec dubium erat quīn, sī tam paucī simul obīre omnia possent, terga datūrī hostēs fuerint (Livy)^[197]

'nor was there any doubt that if it were possible for so few to manage everything at once, the enemy would have turned their backs'

Exactly the same sequence of tenses is used if the conditional sentence is part of a consecutive clause instead of a quī-clause:^[195]

ea rēs tantum tumultum et fugam praebuit ut nisi castra Pūnica extrā urbem fuissent, effūsūra sē omnis pavida multitūdō fuerit (Livy)^[198]

'that situation caused so much panic that if the Carthaginian camp hadn't been situated outside the city, all the frightened mob would have poured out'

Similarly the perfect subjunctive potuerit, not the pluperfect potuisset, is also usually used even after an historic-tense introductory verb to express a passive verb:

haud dubium erat quīn, nisi ea mora intervēnisset, castra eō diē Pūnica capī potuerint (Livy)^[199]

'there was no doubt that if the delay had not intervened, the Carthaginian camp could/would have been captured that day'

Occasionally, however, after a historic verb the pluperfect subjunctive fuisset is used, but this is rare, and found only in Livy:^[195]

subībat cōgitātiō animum quōnam modō tolerābilis futūra Etrūria fuisset, sī quid in Samniō adversī ēvēnisset (Livy)^[200]

'it occurred to them how impossible Etruria would have been, if anything had gone wrong in Samnium'

The following example is unusual in that it envisages a future event that might one day have taken place if a past situation had been different. The tense used in the apodosis is the imperfect subjunctive:^[201]

sī tum P. Sestius animam ēdidisset, nōn dubitō quīn aliquandō statua huic in forō statuerētur (Cicero)^[202]

'if at that time Publius Sestius had died, I do not doubt that one day a statue would be set up to this man in the forum'

Indirect questions with sī

In classical Latin, indirect questions are almost never introduced by sī. Instead, after the verb quaerō 'I ask', the simple suffix -ne is usually used:

quaesīvī cognōsceretne signum; adnuit (Cicero)^[203]

'I asked if he recognised the seal; he nodded'

However, Livy sometimes uses sī:^[204]

nihil aliud locūtum ferunt quam quaesīsse, sī incolumis Lycortās equitēsque ēvāsissent (Livy)^[205]

'it is reported that he said nothing else except to ask if Lycortas and the cavalrymen had escaped unharmed'

According to Lewis and Short's dictionary,^[206] this usage derives from the meaning 'to see if by chance' described above. A sentence where this meaning after quaerō is more evident is the following:

quaero diū tōtam per urbem, sī qua puella neget: nulla puella negat (Martial)^[207]

'I have been searching for a long time through the whole city (to see) if any girl will say no; not one says no'

Another place where 'if' is used in modern languages is in expressions such as 'I don't know if ...'. However, in classical Latin after nesciō or haud sciō 'I do not know', it is usual to use the particle an:

nōn possum scīre, an eī prōfutūrus sim, quem admoneō (Seneca)^[208]

'I have no way of knowing if I am going to be of benefit to the person I am advising'

The use of sī in such sentences is very rare, although the following is cited:

sed fātīs incerta feror, sī Iuppiter ūnam esse velit Tyriīs urbem Troiāque profectīs (Virgil)^[209]

'but I am being tossed by the Fates, uncertain whether Jupiter wishes there to be one city for the Tyrians and the refugees from Troy'

The use of sī in both types of sentence is recorded in medieval Latin, however.^[210]