Jussive mood

The jussive (abbreviated ) is a grammatical mood of verbs for issuing orders, commanding, or exhorting (within a subjunctive framework). English verbs are not marked for this mood. The mood is similar to the cohortative mood, which typically applies to the first person by appeal to the object's duties and obligations, and the imperative, which applies to the second (by command). The jussive however typically covers the first and third persons. It can also apply to orders by their author's wish in the mandative subjunctive.

Examples

German
In the German language, the jussive mood is expressed using the present subjunctive (named "Konjunktiv I" or "Möglichkeitsform I" in German). It is typical of formal documents or religious texts, such as the Bible. Because it was more common in past centuries, it has often survived in proverbs:

{|
|Es||kehre||jeder||vor||seiner||eigenen||Tür.
|-
|It||sweep+++||everyone||in front of||his||own||door
|-
|colspan="7"|Everybody should sweep in front of his own door (Everybody should mind his own business).
|}

It is still common that recipes are written in jussive mood:
{|
|Man||nehme||drei||Eier
|-
|One||take+++||three||eggs
|-
|colspan=4|Take three eggs
|}

Apart from that, jussive mood is still quite common in contemporary German. However, the pronouns he, she, and it might not be used directly; otherwise jussive would be mistaken for a dated form of courteous imperative. Instead, they will have to be replaced by "who", "someone", "everyone", "the new colleague" and so on:

{|
|Wer||noch||eine||Karte||braucht, ||melde||sich||bei||mir
|-
|Who||still||a||ticket||need+++, ||report+++||self||at||me
|-
|colspan=9|If someone still needs a ticket, just contact me.
|}

Finally an example for jussive that would have served as a courteous imperative when addressing people of lower, but not lowest, rank:

{|
|Komme||Er||her||und||helfe||Er||mir!
|-
|come+++||he||here||and||help+++||he||me!
|-
|colspan=8|Come over and help me!
|}

Note that Er is written in capital letters here. Even if this construction is not used anymore in common German, it will be recognized as being an imperative (German Wikipedia lists the example "Sei Er nicht so streng!" as a historic form of an imperative).

Latin
In the Latin language, the present subjunctive can convey jussive meaning in the third person (jussive subjunctive or coniunctivus iussivus):
Adiuvet ("Let him help.")
Veniant ("Let them come.")

A jussive use of the present subjunctive is also attested for the second person in sayings and poetry, as well as in early Latin.
iniurias fortunae [...] relinquas ("Leave behind [...] the wrongs of Fortune", saying from Cicero's Tusculanae Disputationes)
doceas iter ("Show us the way", poetry from Virgil's Aeneid)

Russian
The jussive mood in modern Russian serves as an imperative (for issuing orders, commanding or requesting), but covers third person instead of second person. Always formed with a particle пусть, which is derived from the verb пускать (to let, to allow).

Imperative: Беги! (Run!)
Jussive: Пусть бежит (similar to Let him run)

Finnish
While there is a separate imperative form in Finnish, the jussive mood is used for the third person, where the imperative is not suitable. The jussive's ending is -koon ~ -köön in the singular and  -koot ~ -kööt in the plural. The jussive can be used to express speakers' positions or opinions that somebody is allowed to do something or that somebody is expected to do something. 
Eläköön! ("Let-he/she/it-live", Hooray!)
Noudattakoon ("person-is-declared-to-obey", typical expression in legislative context)
Tapahtukoon tahtosi ("Let-it-happen your-will", let thy will be done)

Esperanto
The jussive mood, called the volitive in Esperanto, is used for wishing and requesting, and serves as the imperative. It covers some of the uses of the subjunctive in European languages:
Iru! (Go!)
Mi petis, ke li venu. (I asked him to come.)
Li parolu. (Let him speak.)
Ni iru. (Let's go.)
Benu ĉi tiun domaĉon. (Bless this hovel.)
Mia filino belu! (May my daughter be beautiful!)

Arabic
Classical and Standard Arabic verbs conjugate for at least three distinct moods in the imperfect: indicative, subjunctive and jussive. In the dialects, these moods are not morphologically marked.

The jussive is used after the preposition li- 'to' to express a command to a third person.

li-yaf‘al-hu
to-do-it
'Let him do it.'

A further use of this mood is in negative commands.

lā ta’xudh dhālika l-laḥm
not take that the-meat
'Don't take that meat.'

The jussive form is also used in past tense sentences negated by lam (but not mā).

lam ta’kuli d-dajāj
not eat the-chicken
'She didn't eat the chicken.'

References

Further reading

Category:Grammatical moods