This is the 968th most frequent Finnish word.
niissä
"Niissä" means "in them" or "in those" in English.
Here, 'niissä' refers to 'those' and is used to locate something within the books.
Niissä kirjoissa on paljon tietoa.
Those books contain a lot of information.
Here, 'niissä' refers to 'those' and is used to describe the context of the situations.
Niissä tilanteissa on hyvä pysyä rauhallisena.
In those situations, it is good to remain calm.
Here, 'niissä' means 'in them' and indicates an inclusion or possession of special qualities.