When; whenever.
Marks a sentence that expresses a state or happening that is either closely followed by a state or happening expressed by a following sentence or occurs simultaneously with it.
Wa ay ta nawā'ahan gun'a mamallo' ti un'a napāyad.
Whenever it is daytime you continually sleep because you are lazy.
Wa ay ta mi'id tigon Iyu ay hiya ya innalna anu din batu.
When Iyu would not be looking at him he would get that stone.
See sec. 7.26.2.4.