This is the 730th most frequent Finnish word.
jäävät
"Jäävät" means "they stay" or "they remain" in English.
Here, 'jäävät' means 'stay' or 'remain' as in the context of tourists choosing to remain in Finland.
Monet turistit jäävät Suomeen nauttimaan maisemista.
Many tourists stay in Finland to enjoy the scenery.
In this sentence, 'jäävät' indicates the students remain at the school post-class hours to continue their activities.
Oppilaat jäävät usein koulun jälkeen tekemään tehtäviä.
Students often stay after school to do their assignments.
Here, 'jäävät' is used to describe the process of lakes freezing, reflecting a change of state into being covered by ice.