Optative, jussive, permissive (3rd person)

The suffix -SIN conveys the speaker's expectation towards a (3rd) person or state of things, whether it is a wish (optative), an obligation (jussive) or a permission (permissive).
If several persons are concerned (3rd person plural), the suffix is pluralized in -SINLAR.

● The optative conveys the speaker's attitude of hope or wish directly oriented towards a person or a state of thing.

Shu gaping to'g'ri bo'lsin.
May those words of yours come true.

Yordam bersin.
May god help us.

● The jussive signals the speaker's command that the proposition he expresses be brought about.

Kelsin!
Let him come!

Sovchilar kimning qiziga borsin?
To which girl's family should go the matchmaker?

● The permissive signals the speaker's permission or agreement that the proposition he expresses be brought about.

Bilsinlar.
Let them know.