Verbs have plural forms in the 1st, 2nd, and 3rd person. In the 3rd person plural, the suffix is vat or vät. The predicate is normally in plural if the subject is in plural, e.g. mies juoksee (a man is running) but miehet juoksevat (men are running).
In common spoken language, however, singular forms are used in the 3rd person even when the subject is in plural, e.g. miehet juoksee.
As described in the preceding section, congruence does not apply even in standard language when the subject denotes a single entity, despite having plural form, e.g. Yhdysvallat teki aloitteen (The United States made a proposal).
Even in standard language, singular verb forms are used instead of plural in some contexts. When the subject contains a numeral, the verb is in singular, when the subject refers to an indefinite set, e.g. Kolme miestä juoksee pihalla (There are three men running on the yard). When the subject is definite, so that we would use “the” in English, the verb is in plural: Kolme miestä juoksevat pihalla (The three men are running on the yard). Such expressions really do not sound natural without at least some demonstrative pronoun (used in an article-like manner) or other addition, e.g. Ne kolme miestä juoksevat pihalla.
Sometimes the use of singular vs. plural verb form even makes a difference in meaning, in standard Finnish:
However, since common spoken language uses singular (kävi) in both examples, it would be unrealistic to rely on such devices. In practice, one would rather say Kaksi sisaristani… in the latter case.