Conditional Sentences

I. Introduction

• Si legunt, inveniunt disciplinam.
• If they read (protasis), they acquire knowledge (apodosis).

We may categorize conditional sentences according to just how likely it is that the premise of the statement is realized and the conclusion occurs.  Thus, although all conditions contain by definition an element of doubt, the indicative mood is employed to express a relative degree of certainty, while the subjunctive mood is used for cases in which the outcome is either less certain or totally precluded by past or present circumstances.  Conditional sentences are further categorized according to whether the action takes place in past, present, or future time.

Notes:

• A standard formula for the translation of each type of conditional sentence is presented here.  Remember, because the tenses in these complex sentences have a relative sense, and because the meaning of the apodosis is dependent upon that of the protasis, one must first determine the type of condition before attempting a translation.
• I have divided and typed the sample sentences in the way which makes the most sense to me, but please take note of this common variation:
• Conditional Sentences using the indicative mood and expressing a likely result are often referred to as Logical Conditional Sentences.
• Those using the subjunctive mood and expressing an uncertain supposition are often called Ideal Conditional Sentences.
• Finally, those using the subjunctive mood and expressing an unfulfilled or impossible result are often called Unreal Conditional Sentences.

II. The Conditional Particles

• si expresses the affirmative condition under which the action of the apodosis follows.
• nisi implies that the action of the apodosis follows logically except in the particular case supposed.
• si non implies that the action of the apodosis follows logically only in the negative case supposed.
• Other particles sometimes used to indicate conditionality are the correlatives sive... sive, whether... or; nisi si, except if; the ironic nisi vero and nisi forte, unless indeed;  and sin, but if.

III. The Types of Conditions

Simple Present and Past Conditions

• Si legunt, inveniunt disciplinam.
• If (whenever) they read, they acquire knowledge.
• Simple Present Condition.  Translate both verbs as present indicatives.
• Si legebant, inveniebant disciplinam.
• If (whenever) they read, they acquired knowledge.
• Simple Past Condition.  Translate both verbs as past indicatives.

NOTE:
In Simple Conditions, sense may dictate that the apodosis assume another form, such as a  hortatory subjunctive or an imperative.  This change is restricted to the main clause of the sentence and affects neither the grammar nor the conditional sense of the subordinate clause:
• Si vis invenire disciplinam, lege.
• If you wish to acquire knowledge, read.

Future Conditions

• Si legent, invenient disciplinam.
• If they read (will read), they will acquire knowledge.
• Future More Vivid Condition.  Translate the verb in the protasis as a present indicative, the verb in the apodasis as a future.
• Si legant, inveniant disciplinam.
• If they should read, they would acquire knowledge.
• Future Less Vivid Condition.  Translate using the formula should/would.

NOTES:
In Future Conditions, the perfect tense may be substituted in the protasis in order to convey a sense of completion relative to the action of the apodosis.  In rare cases, the perfect indicative will be found in the apodosis with a present or a future perfect in the protasis in order to convey the sense of a forgone conclusion.
• Si legerunt, invenient disciplinam.
• If they have read (in the past), they will acquire knowledge (in the future).
• Si legerint, invenerunt disciplinam.
• If they shall have read, they have (already) aquired knowledge.
The future perfect, or any other form conveying future time, may appear in the apodosis of Future Conditions without any significant change in sense.

Contrary to Fact Conditions

• Si legerent, invenirent disciplinam.
• If they were reading (but they are not), they would be acquiring knowledge.
• Present Contrary to Fact Condition.  Translate using the formula were/would be.
• Si legissent, invenissent disciplinam.
• If they had read (but they did not), they would have acquired knowledge.
• Past Contrary to Fact Condition.  Translate using the formula had/would have.


NOTES:
The imperfect in both the protasis and apodosis sometimes carries a past sense if it refers to repeated or continued action.

• Si nihil legerent, numquam invenirent disciplinam.
• If they had read nothing at all, they never would have acquired knowledge.
An indicative may be substituted in the apodosis of a Contrary to Fact Condition in order to express that the action was intended, likely, or already initiated.  If the action of the apodosis has a sense of necessity or possibility, the verb may be in the imperfect or perfect indicative.

IV.  Other Types of Conditionals

Relative Conditionals

• Qui leget, inveniet disciplinam.
• He who reads (protasis), will acquire knowledge (apodosis). [=If anyone reads, he will acquire knowledge.]
• Future More Vivid Relative Condition.

• Quisquis aliquid poesis legit, invenit disciplinam.
• Whoever reads something of poetry (if anyone reads something of poetry), he acquires knowledge.
• Simple Present Relative Condition.
• Quaecumque legisset, invenisset disciplinam.
• Whatsoever he had read (if he had read anything at all), he would have acquired knowledge.
• Past Contrary to Fact Relative Cdondition.

General Conditionals

• Si quid magister dicat, auditur.
• If the teacher says something (whenever he says anything), he is (always) heard.
• Present General Condition.
• Si quid magister diceret, audiebatur.
• If the teacher said something (whenever he said anything), he was (always) heard.
• Past General Condition.

V.  Concluding Note