Conditional sentences are natural language sentences that express that one thing is contingent on something else, e.g. "If it rains, the picnic will be cancelled." They are so called because the impact of the main clause of the sentence is conditional on the dependent clause. A full conditional thus contains two clauses: a dependent clause called the antecedent (or protasis or if-clause), which expresses the condition, and a main clause called the consequent (or apodosis or then-clause) expressing the result.
Languages use a variety of grammatical forms and constructions in conditional sentences. The forms of verbs used in the antecedent and consequent are often subject to particular rules as regards their tense, aspect, and mood. Many languages have a specialized type of verb form called the conditional mood – broadly equivalent in meaning to the English "would (do something)" – for use in some types of conditional sentences.
There are various ways of classifying conditional sentences. Many of these categories are visible cross-linguistically.
A conditional sentence expressing an implication (also called a factual conditional sentence) essentially states that if one fact holds, then so does another. (If the sentence is not a declarative sentence, then the consequence may be expressed as an order or a question rather than a statement.) The facts are usually stated in whatever grammatical tense is appropriate to them; there are not normally special tense or mood patterns for this type of conditional sentence. Such sentences may be used to express a certainty, a universal statement, a law of science, etc. (in these cases if may often be replaced by when):
They can also be used for logical deductions about particular circumstances (which can be in various mixtures of past, present, and future):
A predictive conditional sentence concerns a situation dependent on a hypothetical (but entirely possible) future event. The consequence is normally also a statement about the future, although it may also be a consequent statement about present or past time (or a question or order).
One of the most discussed distinctions among conditionals is that between indicative and counterfactual conditionals, exemplified by the following English examples:
These conditionals differ in both form and meaning. The indicative conditional uses the present tense forms "owns" and "beats" and therefore conveys that the speaker is agnostic about whether Sally in fact owns a donkey. The counterfactual example uses the fake tense form "owned" in the "if" clause and the past-inflected modal "would" in the "then" clause. [1] As a result, it conveys that Sally does not in fact own a donkey. [2] Similar contrasts are common crosslinguistically, though the specific morphological marking varies from language to language. [3] [4] [5] [6]
Linguists and philosophers of language sometimes avoid the term counterfactuals because not all examples express counterfactual meanings. For instance, the "Anderson Case" has the characteristic grammatical form of a counterfactual conditional, but is in fact used as part of an argument for the truth of its antecedent. [7] [8]
The term subjunctive conditional has been used as a replacement, though it is also acknowledged as a misnomer. Many languages do not have a subjunctive (e.g., Danish and Dutch), and many that do have it don’t use it for this sort of conditional (e.g., French, Swahili, all Indo-Aryan languages that have a subjunctive). Moreover, languages that do use the subjunctive for such conditionals only do so if they have a specific past subjunctive form. [10] [11] [12] The term X-Marked has been used as a replacement, with indicative conditionals renamed as O-Marked conditionals. [13] [14] [15]
Biscuit conditionals (also known as relevance or speech act conditionals) are conditionals where the truth of the consequent does not depend on the truth of the antecedent.
In metalinguistic conditionals, the antecedent qualifies the usage of some term. For instance, in the following example, the speaker has unconditionally asserted that they saw the relevant person, whether or not that person should really be called their ex-husband. [17]
In conditional questions, the antecedent qualifies a question asked in the consequent. [18] [19]
In conditional imperatives, the antecedent qualifies a command given in the consequent. [20]
Languages have different rules concerning the grammatical structure of conditional sentences. These may concern the syntactic structure of the antecedent and consequent clauses, as well as the forms of verbs used in them (particularly their tense and mood). Rules for English and certain other languages are described below; more information can be found in the articles on the grammars of individual languages. (Some languages are also described in the article on the conditional mood.)
Conditional sentences in Latin are traditionally classified into three categories, based on grammatical structure.
In French, the conjunction corresponding to "if" is si. The use of tenses is quite similar to English:
As in English, certain mixtures and variations of these patterns are possible. See also French verbs.
Italian uses the following patterns (the equivalent of "if" is se):
See also Italian verbs.
In Slavic languages, such as Russian, clauses in conditional sentences generally appear in their natural tense (future tense for future reference, etc.) However, for counterfactuals, a conditional/subjunctive marker such as the Russian бы (by) generally appears in both condition and consequent clauses, and this normally accompanies the past tense form of the verb.
See Russian grammar, Bulgarian grammar, etc. for more detail.
While the material conditional operator used in classical logic is sometimes read aloud in the form of a conditional sentence, the intuitive interpretation of conditional statements in natural language does not always correspond to it. Thus, philosophical logicians and formal semanticists have developed a wide variety of conditional logics that better match actual conditional language and conditional reasoning. They include the strict conditional and the variably strict conditional. [21] [22] [23]
In grammar, tense is a category that expresses time reference. Tenses are usually manifested by the use of specific forms of verbs, particularly in their conjugation patterns.
The subjunctive is a grammatical mood, a feature of an utterance that indicates the speaker's attitude toward it. Subjunctive forms of verbs are typically used to express various states of unreality such as wish, emotion, possibility, judgment, opinion, obligation, or action that has not yet occurred; the precise situations in which they are used vary from language to language. The subjunctive is one of the irrealis moods, which refer to what is not necessarily real. It is often contrasted with the indicative, a realis mood which principally indicates that something is a statement of fact.
Counterfactual conditionals are conditional sentences which discuss what would have been true under different circumstances, e.g. "If Peter believed in ghosts, he would be afraid to be here." Counterfactuals are contrasted with indicatives, which are generally restricted to discussing open possibilities. Counterfactuals are characterized grammatically by their use of fake tense morphology, which some languages use in combination with other kinds of morphology including aspect and mood.
In Portuguese grammar, nouns, adjectives, pronouns, and articles are moderately inflected: there are two genders and two numbers. The case system of the ancestor language, Latin, has been lost, but personal pronouns are still declined with three main types of forms: subject, object of verb, and object of preposition. Most nouns and many adjectives can take diminutive or augmentative derivational suffixes, and most adjectives can take a so-called "superlative" derivational suffix. Adjectives usually follow their respective nouns.
In linguistics, irrealis moods are the main set of grammatical moods that indicate that a certain situation or action is not known to have happened at the moment the speaker is talking. This contrasts with the realis moods. They are used in statements without truth value
The pluperfect, usually called past perfect in English, characterizes certain verb forms and grammatical tenses involving an action from an antecedent point in time. Examples in English are: "we had arrived" before the game began; "they had been writing" when the bell rang.
In French grammar, verbs are a part of speech. Each verb lexeme has a collection of finite and non-finite forms in its conjugation scheme.
The sequence of tenses is a set of grammatical rules of a particular language, governing the agreement between the tenses of verbs in related clauses or sentences.
The conditional mood is a grammatical mood used in conditional sentences to express a proposition whose validity is dependent on some condition, possibly counterfactual.
While the English language lacks distinct inflections for mood, an English subjunctive is recognized in most grammars. Definition and scope of the concept vary widely across the literature, but it is generally associated with the description of something other than apparent reality. Traditionally, the term is applied loosely to cases in which one might expect a subjunctive form in related languages, especially Old English and Latin. This includes conditional clauses, wishes, and reported speech. Modern descriptive grammars limit the term to cases in which some grammatical marking can be observed, nevertheless coming to varying definitions.
The conditional perfect is a grammatical construction that combines the conditional mood with perfect aspect. A typical example is the English would have written. The conditional perfect is used to refer to a hypothetical, usually counterfactual, event or circumstance placed in the past, contingent on some other circumstance. Like the present conditional, the conditional perfect typically appears in the apodosis in a conditional sentence.
In linguistics, speech or indirect discourse is a grammatical mechanism for reporting the content of another utterance without directly quoting it. For example, the English sentence Jill said she was coming is indirect discourse while Jill said "I'm coming" would be direct discourse. In fiction, the "utterance" might amount to an unvoiced thought that passes through a stream of consciousness, as reported by an omniscient narrator.
In linguistics, grammatical mood is a grammatical feature of verbs, used for signaling modality. That is, it is the use of verbal inflections that allow speakers to express their attitude toward what they are saying. The term is also used more broadly to describe the syntactic expression of modality – that is, the use of verb phrases that do not involve inflection of the verb itself.
Tense–aspect–mood or tense–modality–aspect is an important group of grammatical categories, which are marked in different ways by different languages.
In the grammar of Ancient Greek, an aorist is a type of verb that carries certain information about a grammatical feature called aspect. For example, an English speaker might say either "The tree died" or "The tree was dying", which communicate related but distinct things about the tree and differ in aspect. In ancient Greek, these would be stated, respectively, in the aorist and imperfect. The aorist describes an event as a complete action rather than one that was ongoing, unfolding, repeated, or habitual.
Portuguese verbs display a high degree of inflection. A typical regular verb has over fifty different forms, expressing up to six different grammatical tenses and three moods. Two forms are peculiar to Portuguese within the Romance languages:
Modern standard English has various verb forms, including:
Prototypical conditional sentences in English are those of the form "If X, then Y". The clause X is referred to as the antecedent, while the clause Y is called the consequent. A conditional is understood as expressing its consequent under the temporary hypothetical assumption of its antecedent.
Hindustani verbs conjugate according to mood, tense, person, number, and gender. Hindustani inflection is markedly simpler in comparison to Sanskrit, from which Hindustani has inherited its verbal conjugation system. Aspect-marking participles in Hindustani mark the aspect. Gender is not distinct in the present tense of the indicative mood, but all the participle forms agree with the gender and number of the subject. Verbs agree with the gender of the subject or the object depending on whether the subject pronoun is in the dative or ergative case or the nominative case.
The subjunctive is one of the three moods that exist in the Spanish language. It usually appears in a dependent clause separated from the independent one by the complementizer que ("that"), but not all dependent clauses require it. When the subjunctive appears, the clause may describe necessity, possibility, hopes, concession, condition, indirect commands, uncertainty, or emotionality of the speaker. The subjunctive may also appear in an independent clause, such as ones beginning with ojalá ("hopefully"), or when it is used for the negative imperative. A verb in this mood is always distinguishable from its indicative counterpart by their different conjugation.