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.

(1a) ūɣ-əm kəčə woʌ-m-aʌ-at, mā lēkar-nam mən-əm.

head-1sg sick be-pst.ptc-3sg-fin I doctor-apr go-pst.1sg

‘Because I had a headache, I went to see the doctor.’ (L. N. K.)

(1b) mā lēkar-nam ťūt-at mən-əm, ūɣ-əm kəčə woʌ.

I doctor-apr that-fin go-pst.1sg head-1sg sick be.pst.3sg

‘I went to see the doctor because I had a headache.’ (L. N. K.)

(2a) wertaljot ʌüw-at əntə wəj-m-aʌ pətan mīša wɔ̄č-nam əntə mən.

helicopter he-acc neg pick_up-pst.ptc-3sg because Misha town-apr neg go.pst.3sg

‘Misha didn’t go to the town because the helicopter didn’t pick him up.’ (L. N. K.)

(2b) mīša wɔ̄č-nam əntə mən ťūt-at, čəkə wertaljot ʌüw-at əntə wəj.

Misha town-apr neg go.pst.3sg that-fin because helicopter he-acc neg pick_up.pst.3sg

‘Misha didn’t go to the town because the helicopter didn’t pick him up.’ (L. N. K.)

(3) əj-pa nāj üʌ-t-a pətan pōm säwə-lə-t-a ura əntə jə-ʌ!

one_time fire set-prs.ptc-2sg because grass braid-dim-pl-lat trouble neg become-prs.3sg

‘Nothing will happen to your little grass-braids because of your having set the fire once.’ (Aypin 2002: 5.)

Traditionally, causal relationships are coded by participles (present or past participles) in Surgut Khanty. Due to the fact that the cause usually precedes the main event, past participles are more frequent, which take the -at instructive-finalis suffix (1a) or the pәtan ‘because’ postposition (2a). Present participles are rare (3). In recent texts, constructions that entail connectives and/or conjunctions, and two finite verbs have also appeared (1b), (2).