Finnish, especially the modern literary dialect, abounds in compound nouns, in which the last word of the compound is defined by that which precedes it, so that the first word is practically an adjective. Thus in pääkaupunki, a capital, kaupunki means a town, and the word pää, a head, describes what sort of town is intended. So also rautatie, a railway, from rauta, iron, and tie, a road; tullihuone, a custom house; puutarha, a garden (puu, a tree, tarha, an enclosure), kirkkotarha, a churchyard (kirkko, church, tarha, enclosure). Sometimes the first word is an adjective, as omatunto, conscience, from oma, own, and tunto, feeling. This is written as one word, because omatunto conveys a different meaning from the separate words oma and tunto.
When a compound is made up of more than two words, all but the last may be regarded as a single word qualifying the last, and then be decomposed in their turn. For instance in ylioppilaskirjasto, University students’ library, kirjasto, library, is qualified by ylioppilas, describing what kind of a library is meant, and in this word ylioppilas, oppilas, student, is particularised by the addition of yli. Similarly isänmaanrakkaus, patriotism, is composed of isänmaa, fatherland, and rakkaus, love, and isänmaa again is composed of isä, father, and maa, land.
Generally the first word of a compound is used in the nominative case. Sairashuone, a hospital (stem sairaha). Frequently, however, it is in the genitive, this case being either (a) descriptive, as in maantie, highroad, literally road of the land: talonpoika, peasant, literally son of a farm; (b) subjective, that is to say, if the compound were developed into a phrase the word in the genitive would become the subject, as kuunvalo, moonlight; (c) objective, that is to say, if the compound were developed into a phrase the word in the genitive would become the object, hatuntekijä, a hatmaker.
More rarely other cases are used, as toimeentulo, subsistence, kuntoonpano, arrangement, accomplishment.
As a rule, only the last word of a compound is declined, the preceding member remaining unaffected by inflection. But if the first member is an adjective, then both parts of the word receive inflections, e.g. vierasmies, a stranger, forms the genitive vieraanmiehen, inessive vieraassamiehessä, etc. But vierasmiehen is not wrong.
THE ADJECTIVE.
Adjectives are declined exactly like substantives, and like them have no gender.
Besides declension they are susceptible of inflections indicating the comparative and superlative degrees.