Question about ている ていた for explaining state for something


What is difference between 財布が落ちていた and 財布が落ちている? Both refer to the state of
財布, right? So, what is the difference?

(My main question is I want to know the difference between (が/は)～ていた and
(が/は)～ている when they refer to the state of something)




財布が落ちている refers to the _current_ state of the wallet. The wallet fell in the
past, and you are seeing its result _now_.

財布が落ちていた is relatively more complicated because it involves two different time
points in the past. 財布が落ちていた refers to the state of the wallet _in the past_.
It describes what the wallet _was_ like at the time of a certain event in the
past. When you saw a wallet on the street yesterday, and want to report that
fact _now_ , you say 昨日道に財布が落ちていた. We are not interested in the current status
of the wallet.

Let me reintroduce the diagram I made for [another similar
question](https://japanese.stackexchange.com/q/57193/5010). This uses other
instant state-change verbs (帰る/割れる) as examples, but 落ちる is also an instant
state-change verb. "Point of change" refers to the time when someone dropped
the wallet, and the eye icon indicates the time you perceive(d) that fact.

[![past/present
perfective](https://i.stack.imgur.com/dY6BD.png)](https://i.stack.imgur.com/dY6BD.png)

