mõistnud

Mõistnud is the past active participle of the Estonian verb mõistma, meaning "to understand." It conveys the sense of “having understood” and is used to indicate that the act of understanding has been completed. The participle itself does not specify tense; Estonian forms tense and mood in combination with the auxiliary verb olema (to be), as in the present perfect olen mõistnud or the past perfect olin mõistnud.

In ordinary usage mõistnud appears in compound tenses to express understoodness in relation to another event or time. It can also function in participial clauses or as an attributive modifier, agreeing with a noun in number and case when used adjectivally. For example, it can appear in sentences that mean “I have understood” or “Having understood, I ...” depending on the surrounding structure.

Usage notes:

- Tense is indicated by the finite form of olema: olen mõistnud (I have understood), olin mõistnud (I had understood).

- The participle can introduce a subordinate clause meaning “having understood” (e.g., Mõistnud, et ta pidi lahkuma, otsustas ta jääda veidi kauem — Having understood that he had to leave, he decided to stay a little longer).

- It is related to the root mõistma and is part of standard Estonian participle system; it is common in both spoken and written language, including formal contexts.

See also: mõistma, mõistvus.