The first two can be rewritten:
People appreciate me.
People understand me.
This suggests that they are passive. The last two are adjectival; the person is either tired or has finished. There's a grey area where it can be unclear whether a past participle is being used as an adjective or in a passive, but you can always try putting by... after it. If it's hard or impossible, then it'll be an adjective in most cases.