eriikäisiin

Eri-ikäisiin is a Finnish compound adjective form meaning “to people of different ages” or “of different ages.” It is the illative plural form of the base adjective eri-ikäinen, formed from eri- (“different”) and ikäinen (“of age”). The form is used to describe groups that include individuals from multiple age groups, and it typically accompanies a noun in the illative case, indicating the target or recipient of action, such as “to the children.”

In practice, eri-ikäisiin is used with a following noun in illative plural, for example eri-ikäisiin lapsiin (to children of different ages) or eri-ikäisiin ryhmiin (into groups of mixed ages). Other inflections exist for the same base: nominative plural eri-ikäiset, partitive plural eri-ikäisiä, and so on, reflecting the noun’s case and number.

Usage notes: eri-ikäisiin is common in contexts dealing with age diversity, such as education, social services, demography, and research. The standard spelling in Finnish is eri-ikäisiin, with a hyphen between eri and ikäinen; omitting the hyphen (eriikäisiin) is rare and generally considered nonstandard.

See also: eri-ikäinen, ikäryhmä, ikä, Finnish morphology.