Not-yet tense is an absolute tense that refers to times at and before the moment of utterance in asserting the present and past nonoccurrence of an event or state. It tends to imply that the event or state is expected to occur in the future.
This tense corresponds to the meaning of the English not yet.
Here is an example of not-yet tense:
te- tu- nna- genda
NEG- we- NOT.YET- go
‘We have not yet gone.’