It buries a question inside a sentence and then says you do not know the answer: no idea what he is on about, not sure whether you can tell, not knowing where it is now, not knowing how we are supposed to do this. Attached to the ending meaning but, it becomes a standard softener before you say something anyway. Be careful with the lookalike spelling that counts elapsed time, as in how long it has been since you did something; that is a different 지 despite the identical sound.