We have now to consider what are the other formative elements used in the Finnish verb, in doing which it is best to take first the finite affirmative conjugation, leaving aside the negative and passive forms. We may also leave aside the compound tenses which have doubtless arisen under foreign influences (cf. the Magyar forms).
We have seen that in nouns the possessive affixes n-sa, m-me, n-ne pointed to the fact that another element besides the strictly pronominal affix was added to the stem. The mme and tte of the plural verb are also best explained as k + me, k + te. This k occurs in many other verbal forms, and is of rather uncertain meaning, but apparently originally used in the present tense. It occurs in most of the cognate languages, particularly Lappish. The moods and tenses of the Finnish verb are very simple. The indicative has but two simple tenses (as in most of the cognate languages), a durative, which answers to both our present and future, and an aorist. There are three other moods, the potential or concessive, which represents an action as possible but not actual, the conditional, and the imperative, with which the optative may be taken to form one tense.
The present indicative adds the personal endings direct to the stem; the other forms add some element between the stem and terminations, which are the same as in the present (n, t, mme, tte, vat), except that the 3rd singular never takes pi or vi.
The past tense (generally called imperfect) is formed by adding the vowel i to the stem, which generally causes euphonic changes. Saa, to receive; sain, I received; anta, to give; annoin, I gave; tule, to come; tulin, I came. This suffix is used in Lappish in the forms je, ie, i, and traces of it occur in Magyar, Mordvinian, Cheremissian, Syrjenian, and Vogul. Ostiak is peculiar in using the simple stem for the past, and adding de to mark the present. The suffix i or je is perhaps the same as ja used to form nouns expressing the agent (e.g. kalastaja, a fisherman). Another termination used extensively in all the Baltic dialects is -si. This is quite regular in verbs whose root ends in ta, for lupat(a)i becomes naturally lupasi, and pyyt(ä)i pyysi (v. p. [16] for detailed rules). But in Esthonian and the South Western dialect of Finnish this termination is added to a great many words which have no t in the stem. E.g. Esthonian: stem palu, pres. palun, pret. palusin; stem pühki, pres. pühin, pret. pühkizin. These forms are perhaps the result of analogy, which was particularly easy on account of the contracted verbs. A comparison of the present lupaan (from which t has been lost) and the imperfect lupasin naturally suggests that si is the characteristic suffix of the latter. On the other hand, Mordvinian, Cheremissian, Vogul, and some forms of Ostiak (as well as the Samoyede languages) all have s or š as a sign of the preterite, so that si may possibly contain another tense element distinct from i.
The concessive is characterised by the syllable ne, or sometimes no in dialects. A conjunctive formed with this element occurs in most of Baltic dialects, Cheremissian, Vogul, and Ostiak.
The conditional has in Finnish a double suffix i + si. The i is doubtless identical with that of the imperfect. The syllable si is no doubt for ksi, for the Esthonian conditional is regularly formed with this suffix. Palu, wiska, pühki, sȫ form paluksin, wiskaksin, pühiksin, sȫksin. Esthonian generally has this suffix without i, but the other Baltic dialects employ the Finnish form. Lappish also has a subjunctive showing the syllable kči, čči, or či, but the form is unknown in the Eastern languages. It is noticeable that both ne and se are found in dialects doubled (myysisin from myy, to sell; tullenen, for tulnenen, from tulla, to come), and also combined in the form neisi, which occurs several times in the Kalevala (e.g. xxiii. 219, 220. Tuosta sulho suuttuneisi Mies nuori nuristuneisi).
The imperative consists of a 2nd person singular, which in literary Finnish is merely the root in a closed form (anna, ota from anta, otta), but which in dialects is found ending in k (annak, otak, etc.), and of a 1st and 2nd plural ending in kaamme, kaatte (or kaa) in the literary language, though kama, kamme, katte are also found. A 3rd person singular in kaan also occurs, but rarely. The optative consists of a 2nd person singular ending in os, of a 3rd person singular in koon, and a 3rd person plural in koot. These forms have been generally explained as weakenings of suffixes kasa (kaha) and koso (koho), and as representing kasamme, kasatte, koso, koson, and kosot. It appears to me that the evidence brought forward by Setälä (p. 111 ff.) disproves this theory. He points out (1) that the forms kaha, koho never occur in those dialects which otherwise preserve h between vowels, e.g. in the illative and passive; (2) that the Eastern dialects change the kaa or kää of the imperative into koa, keä, which change never occurs when an h has been lost. Besides no particular explanation has ever been offered of the suffixes kasa, koso. The proper suffixes then of the imperative and optative are ka, ko, which are obviously related (cf. ne, dialect no, in the concessive). These suffixes appear in Esthonian as gā (dial) and gu, and a suffix ka, k, or traces of it, occurs not only in the Baltic languages, but in all the other members of the group. It seems to be identical with the k which appears in the negative conjugation and elsewhere, and which is the least definite in signification of suffixes merely indicating the verbal character of the root. Thus the 2nd person singular of the imperative is an elementary verbal form without a personal termination. The forms kaamme, kaatte have evidently added to this suffix the personal termination. The long vowel appears to be an invention of the modern literary dialect. In poetry and dialects we find the forms kämme, käme, and käte.
The termination os of the optative is doubtless for ko + s where s represents the 2nd person singular. In Kalevala xxxiii. 257-8 we find a form in kosi, Kun on kuollet kuolkosipa, kaotkosi kun kaonnet, cf. Kanteletar (p. 14, 2nd ed., 1884) Tehkös liito lintuseni. The 3rd person singular ending in koon is undoubtedly for kohon, where the second element represents the 3rd personal pronoun hän or sen. The assimilation of the vowel to the o of ko resembles the phenomena presented by the illative. The plural koot is similarly for kohot, where the second element represents het or set, that is the 3rd personal pronoun with the plural suffix. The terminations kaan and kaat, which occur dialectically, show similar formations with the ka of the imperative.
Besides the forms of the finite active verb discussed above, Finnish also possesses what is called a passive, but is no doubt really an impersonal verb, used in all the tenses but the imperative. From the root tuo come the present tuodahan, imperf. tuotahin, concessive tuotanehen, conditional tuotaisihin. But the root ending in a short vowel like repi makes revitähän, revittihin, revittänehen, revittäisihin. In all these forms the last element is obviously a termination h-n, which is vocalized analogously to the illative. This is probably the 3rd personal pronoun hän or sen. Besides this termination there is added to the root the element tta after a short vowel, and ta after a long one. This suffix is probably identical with the causal and transitive terminations ta, tta (p. [110]). Thus the passive forms are really causal verbs used impersonally in the 3rd person singular.