Fysisiin

Fysisiin is a Finnish grammatical form that functions as the illative plural of the adjective fyysinen, meaning physical. It is used when referring to physical aspects, properties, or phenomena in a plural sense, roughly translating to “to the physical [ones/aspects].” In standard Finnish, the illative plural of fyysinen appears as fyysisiin, and may be encountered in phrases such as fyysisiin ominaisuuksiin (into physical properties), fyysisiin ilmiöihin (into physical phenomena), or fyysisiin todisteisiin (into physical evidence).

Morphology and usage follow Finnish adjective declension. Adjectives ending in -inen form their illative plural with the ending -isiin. The base word fyysinen denotes things related to the body or the physical realm, and its forms are commonly found in scientific, medical, and everyday language when contrasting physical aspects with mental, emotional, or abstract ones. The form is also encountered in discussions about physics, biology, sports physiology, and related fields.

Etymology and related terms: fyysinen derives from the Latin physicus via other European languages, with the root meaning related to nature, body, or physical reality. Related Finnish terms include fyysinen (physical), fyysiset (the physical ones, plural nominative), fæyisiksi or fysiikka and fysiologia in contexts of physics and physiology.

See also: fyysinen, fyysiset, fyysika, fysiikka, fysiologia. Note that some nonstandard spellings or typographical variants may occur in informal writing, but fyysisiin is the normative illative plural form in Finnish.