Distributive adverbs and adjectives

Adverbs derived from cardinal numerals with the -ttAin suffix express grouping in sets with the given number of items, e.g. kolmittain means “three at time”, “three by three”, “in groups of three”. These derivations are based on the plural inflectional stem, so they are yksittäin, kaksittain, kolmittain, nelittäin, viisittäin, kuusittain, seitsemittäin, kahdeksittain, and yhdeksittäin.

Such derivations are not used for larger numbers, except for round numbers (powers of ten): kymmenittäin, sadoittain, tuhansittain, miljoonittain, miljardeittain etc. For them, the meaning is “tens of”, “hundreds of” etc., and these words may be used like numerals, with an associated noun in the partitive, e.g. sadoittain ihmisiä (hundreds of people).

There are also cor­re­spond­ing adjectives yksittäinen, kaksittainen etc., but only the first one of them is in common use, meaning “individual, separated, single, isolated”.

For some numbers, there are other distributive adverbs, some of which can be interpreted as instructive plural forms or as other inflected forms. Their meanings are of type “as a group of ...” rather than “in groups of”:

• yksin (alone)
• kaksin ∼ kahdestaan ∼ kaksistaan (as a group of two; but English often uses different phrases, e.g. Olimme siellä kahdestaan = We were there just by ourselves, when “we” is implied to refer to two people)
• kolmisin ∼ kolmestaan ∼ kolmistaan (as a group of three)
• nelisin ∼ nelistään (as a group of four)