(1) If the subject is in the partitive, either sing. or plural, the verb is always in the sing. The real subject of the verb in such cases is not the partitive itself, but such a word as joukko, paljo, or vähä understood before it.
(2) If the subject is a noun with a numeral (which in Finnish requires the partitive after it), the verb is also in the singular.
(3) When the verb olla is used with the adessive in the construction rendered by the verb ‘have’ in English, it always remains in the 3rd sing., no matter what the subject may be.
(4) In proverbs, the Kalevala, and popular speech generally, a singular verb is very frequently found with a plur. nominative. Such an irregularity is clearly rendered much easier and less glaring by the analogy of the cases quoted above.
The verb olla, to be, is sometimes omitted, especially in proverbial phrases.
Oma maa mansikka, muu maa mustikka, one’s own land is a strawberry, foreign lands are only blackberries. Ei pyyssä kahden jakoa, a partridge is not enough for two.
If the predicate takes the form of an auxiliary with a noun or adjective, this latter may be put in several cases.
I. In the nominative, when the complement expresses a quality inherent in the subject, without any reference to other things.
II. But it is put in the partitive if the subject is regarded as referred to a class in common with which the subject shares the quality in question.
Thus, veitset ovat terevät means these knives, or the knives are sharp; but veitset ovat teräviä means knives are sharp, or belong to the class of sharp things. Kivi on kova, the stone is hard, i.e. not a soft stone; kivi on kovaa, stone is a hard substance.