Comments: Changing class infixes are attested only in Andian (cf. aor. abaχo / araχo), and it is not quite clear whether it is an archaism or an innovation. In any case, the structure of this verbal stem is quite exceptional. There also exists a reflex of stem II *χʷV- in Tind. χʷē- 'to swell; to rise (of dough)'.