This is the 786th most frequent Finnish word.
saapuu
"Saapuu" means "arrives" in English.
'Saapuu' is used here to describe an event where the train reaches the station, making it an action directly involving arrival.
Juna saapuu asemalle kello kahdeksan.
The train arrives at the station at eight o'clock.
Here, 'saapuu' is utilized metaphorically to depict the transition of time, specifically the evening's onset.
Kun ilta saapuu, taivas muuttuu tummemmaksi.
When the evening arrives, the sky becomes darker.
In this sentence, 'saapuu' is used to indicate the arrival of the train, describing the action of coming to a stated location, track three.