tietäisin

Tietäisin is a Finnish verb form representing the first-person singular present conditional of tietää, meaning “to know.” It expresses hypothetical knowledge or actions contingent on a condition and is used in subordinate clauses introduced by if or in polite, tentative statements. In Finnish, the conditional mood is formed with the suffix -isi- and person endings; for the first person singular the ending is -n, giving tietäisin. The other persons are tietäisit, tietäisi, tietäisimme, tietäisitte, and tietäisivät.

The form is typically used in conditional clauses: “Jos minä tietäisin vastauksen, kertoisin sen” (If I knew the answer, I would tell it). It can also appear in rhetorical questions or polite inquiries such as “Tietäisitkö, mikä aika on?” or “Tietäisikö hän?” The conditional present contrasts with the indicative “tiedän” (I know) and with other mood forms in Finnish grammar.

Historically, tietäisin derives from the verb tietää and the Finnish conditional suffixing system; it is common in both written and spoken Finnish. It is not used as a standalone imperative or imperative-like form, but only within mood-inflected forms or in compound clauses. In everyday use, tietäisin is most often encountered in hypothetical statements and in polite or tentative discourse, where the speaker is contemplating knowledge that is not currently certain.