Action that precedes that of the main clause uses the changed subjunctive conjunct mode.
The preverb –āātan- ‘when’ is often used to introduce these types of sub-phrases.
This variety of ‘when’ has the meaning of ‘’at the time when’ or ‘’back when’ or ‘after that …’
VIIs in the changed subjunctive conjunct mode use initial change and add (-ah) after conjunct suffixes (-k) or the negative (-kw). When using āātan– the initial change is affects āātan– not the verb stem.
Aātan-mxahtāākah ąąnay paθihnāāw. The road cracked after it snowed heavily. Shąąwah āātan-paθihnąąkah, sookunąąn. Right away after it was split in two, it rained. (paθihnāāw be split in two) (first it was split, then it rained) Aātan-sookunąąkah ustah wunutóowih. After it rained, it wasn't pretty. (wunut be pretty, good, nice) Aātan-ahtāākah wunut. When it was there it was nice.
This mode comes in handy for words about the time of day or year.
Wunąąkuw. It is evening. Wāānąąkwíikah. Last evening (changed subjunctive conjunct form) Pnāāyuw. It is night. Pāāpnāāyukah. Last night. (Sw222-j.-av.-73av) Ktak pāāpnāāyukah. Night before last. (Sw222-av.)(Sw167-av116)