17. (4) The final e of a disyllabic stem disappears in nouns before terminations commencing with t, and in verbs before terminations beginning with k or n, provided that e is preceded by any simple consonant but k, p, v, m, or by a double consonant of which the last letter is t or s (except ht). Thus from the stem une (sleep), vuore (mountain), vete (water) (nominative, vesi), come the forms unta, vuorta, vettä, and from the verbal stems tule (come), mene (go), such forms as tulkaa, tullut (for tulnut), menkää. Lapse, a child, forms lasta, for lapsta; veitse, a knife, veistä for veitstä.
But e remains in the verbs potea, to fall ill, tuntea, to know, and in itse, self, suksi, snowshoe, sääksi, a gnat, ripsi, an eyelash, viiksi, a moustache, which form their partitives in itseä, suksea, etc.
18. But in disyllabic words e is not rejected if preceded by k, p, v, or m. Thus the stems joke, river, läpe, a hole, kive, stone, Suome, Finland, form their partitives jokea, läpeä, kiveä, Suomea.
19. Likewise e remains in disyllables where it is preceded by ht, or by any two consonants of which the last is not t or s: tähte, star, and lehte, leaf, form tähteä and lehteä. Onne, fortune, and hanhe, goose, onnea and hanhea.
But yksi, one, and kaksi, two (roots yhte and kahte), form yhtä and kahta for yhttä, kahtta. Lumi, snow, is also an exception and forms lunta. Also the verbal stems teke and näke: infinitive, tehdä, nähdä.
20. In polysyllabic words the e is always suppressed: root kysymykse, a question, partitive case, kysymystä for kysymykstä.
I.
21. (1) When i at the end of substantives meets the i of the plural, the first i changes into e, risti, cross, risteissä. This rule is however not always observed, and forms like ristissä are used for the plural. But in other cases, when two i’s meet, the first falls out, pres. etsivät, imp. etsivät, not etsiivät. In old Finnish, words like etseivät are found.
22. (2) When i (generally owing to the dropping of a consonant) is found between two vowels it becomes j. Kaloia becomes kaloja.
23. All these four vowels, a, ä, e, and i, are rejected before the -i of the terminations of the superlative: vanha, old, selkeä, bright, suure, great, auli, liberal, make in the superlative vanhin, selkein, suurin, aulin.