CauseVBal: The verb of a reason clause obligatorily appears in base form.
CauseVDrk: The verb of a reason clause obligatorily appears in a single special form, regardless of its grammatical features.
(1) āmp ēʟti paltami-man miša jūx-a xūŋxəmt-əs.
dog from get_frightened-conv Misha tree-lat climb-pst.3sg
‘Misha climbed up a tree because he got frightened by a dog.’ (F. L.)
(2) miša wertoľot-n nox at ū-s-a śit ūrǝŋ-ǝn luw wōš-a at mān-s.
Misha helicopter-loc up neg pick-pst-pass.3sg that way-loc he town-lat neg go-pst.3sg
‘Misha didn’t go to the town because the helicopter didn’t pick him up.’ (S. O.)