tiedät

Tiedät is the second-person singular present indicative form of the Finnish verb tietää, meaning “to know.” It is used to express knowledge of a fact, information, or a situation by the person addressed. In Finnish, the subject is often omitted because the verb ending signals the subject.

The infinitive of the verb is tietää. Related present-tense forms include tiedän (I know), tiedät (you know), tietää (he/she/it knows), tiedämme (we know), tiedätte (you know), and tietävät (they know). The past tense forms are tiesin (I knew), tiesit (you knew), tiesi (he/she knew), tiesimme (we knew), tiesitte (you knew), and tiesivät (they knew). The imperative forms are tiedä (singular) and tietäkää (plural), used to command someone to know or to be aware of something.

Usage notes indicate that tiedät is commonly used in questions with the particle -kö/-kö: Tiedätkö mitä tapahtuu? (“Do you know what is happening?”) or Tiedätkö missä hän asuu? The negative form is en tiedä (“I don’t know”). Because Finnish marks agreement in the verb, the subject pronoun is often omitted, as in Sinä tiedät or simply Tiedät.

Etymology and related terms: tietää belongs to a family of words related to knowledge, such as tieto (knowledge or information), tietokone (computer, literally “information machine”), and tietäjä (seer or wise person). The verb is highly productive in everyday language and appears in numerous fixed expressions and collocations.