【芬兰语语法】§20.2 AJATUS NOMINALS

 There are two groups of nominals with a basic form ending in a short

vowel+s. The most common of these is the type ajatus ‘thought’ (cf.

§20.3).

§20.3 TAIVAS NOMINALS

In nominals like taivas ‘heaven’ the -s of the basic form alternates with a

vowel identical with the preceding vowel.

In ajatus nominals -s changes to -kse- in the inflectional stem; the

partitive singular is formed directly from the basic form