Kosteissa

Kosteissa is the inessive plural form of the Finnish adjective kostea, meaning damp or humid. It is used to describe plural nouns in the inessive case, the grammatical form that expresses “in” or “inside” in a locative sense. In practice, kosteissa appears in phrases like kosteissa tiloissa or kosteissa oloissa, translating roughly to “in damp places” or “in humid conditions.”

In Finnish, adjectives inflect to agree with the nouns they modify in number and case. The ending -issa (or -issä after a vowel harmony change) marks the plural inessive; thus kosteissa is paired with a plural noun to convey location or condition. The form is not a standalone noun but part of a broader descriptive expression.

Usage and nuance: kosteissa is common in contexts dealing with housing, building maintenance, environmental health, and weather or climate discussions. It denotes qualitative dampness rather than a precise measurement, which is typically supplied by the accompanying noun or by additional descriptors such as kosteus (“moisture”) or other modifiers.

Examples:

- Kosteissa tiloissa homeen itiöiden kasvu on mahdollista. (In damp spaces, mold spores can grow.)

- Rakenteet voivat vaurioitua kosteissa oloissa. (Structures may deteriorate in humid conditions.)

Related terms include kostea (damp), kosteus (moisture, humidity), and home (mold).