Video narration
How can something be alive once, but never alive again? Think of a leaf on a tree. While attached, it belongs to something living. Then it falls. The leaf was part of life, but it is not alive now. That is the turn: "was alive" describes the past; "is alive" describes the present. The past can stay true without coming back. So yes-it can be alive once, then never be alive again. The leaf's life belongs to its past.