They are used in statements without truth value (imperative, interrogative, subordinate, etc) Every language has grammatical ways of expressing unreality.
Examples include discussing hypothetical or unlikely events, expressing opinions or emotions, or making polite requests (the exact scope is language-specific).
In certain other languages, the dubitative or the conditional moods may be employed instead of the subjunctive in referring to doubtful or unlikely events (see the main article).
A further example of Finnish conditional[14] is the sentence "I would buy a house if I earned a lot of money", where in Finnish both clauses have the conditional marker -isi-: Ostaisin talon, jos ansaitsisin paljon rahaa, just like in Hungarian, which uses the marker -na/-ne/-ná/-né: Vennék egy házat, ha sokat keresnék.
In Polish, the conditional marker -by also appears twice: Kupiłbym dom, gdybym zarabiał dużo pieniędzy.
In French, while the standard language requires the indicative in the dependent clause, using the conditional mood in both clauses is frequently used by some speakers: Si j'aurais su, je ne serais pas venu ("If would have known, I wouldn't have come") instead of Si j'avais su, je ne serais pas venu ("If I had known, I wouldn't have come").
However, J'aurais su, je (ne) serais pas venu is more accepted, as a colloquial form.
In the literary language, past unreal conditional sentences as above may take the pluperfect subjunctive in one clause or both, so that the following sentences are all valid and have the same meaning as the preceding example: Si j'eusse su, je ne serais pas venu; Si j'avais su, je ne fusse pas venu; Si j'eusse su, je ne fusse pas venu.
The optative may not only express wishes, requests and commands, but also possibilities, e.g., kadaacid goshabdena budhyeta "he might perhaps wake up due to the bellowing of cows",[15] doubt and uncertainty, e.g., katham vidyaam Nalam "how would I be able to recognize Nala?"
The jussive mood (abbreviated JUS) expresses plea, insistence, imploring, self-encouragement, wish, desire, intent, command, purpose or consequence.
(In Japanese it is often called something like tentative, since potential is used to refer to a voice indicating capability to perform the action.)
In Japanese the verb inflection -tai expresses the speaker's desire, e.g., watashi wa asoko ni ikitai "I want to go there".
This form is treated as a pseudo-adjective: the auxiliary verb garu is used by dropping the end -i of an adjective to indicate the outward appearance of another's mental state, in this case the desire of a person other than the speaker (e.g. Jon wa tabetagatte imasu "John appears to want to eat").
"[20] The presumptive mood is used in Romanian and Hindi to express presupposition or hypothesis, regardless of the fact denoted by the verb, as well as other more or less similar attitudes: doubt, curiosity, concern, condition, indifference, inevitability.
Often, for a sentence in presumptive mood, no exact translation can be constructed in English which conveys the same nuance.
The same structure for a particular grammatical aspect can be used to refer to the present, past and future times depending on the context.
[21][22] The table below shows the conjugations for the presumptive mood copula in Hindi and Romanian with some exemplar usage on the right: Note: The hortative or hortatory mood is used to express plea, insistence, imploring, self-encouragement, wish, desire, intent, command, purpose or consequence.
The inferential mood (abbreviated INFER or INFR) is used to report a nonwitnessed event without confirming it, but the same forms also function as admiratives in the Balkan languages in which they occur.
The inferential mood is used in some languages such as Turkish to convey information about events that were not directly observed or were inferred by the speaker.
The second pair implies either that the speaker did not in fact witness it taking place, that it occurred in the remote past, or that there is considerable doubt as to whether it actually happened.