õpetanud

õpetanud is the past active participle of the Estonian verb õpetama, meaning to teach. It expresses that the act of teaching has taken place in the past and can function as a participle or as an attributive adjective. In combination with the auxiliary verb olema, it forms the perfect aspect, as in olen õpetanud (I have taught) or on õpetanud (has taught).

As a participle, õpetanud can modify a noun to describe someone who has taught, or it can appear in predicative constructions with the auxiliary, indicating a completed teaching action. The form is declined like an adjective, aligning with number and case of the noun it accompanies. The base form used in dictionaries is the singular nominative, while other cases receive appropriate endings in context.

Etymology and related forms: õpetanud derives from the verb õpetama (to teach). It is cognate with related Finnic forms such as Finnish opettaa and opettanut, reflecting common Finno-Ugric roots for the concept of teaching. The participle is part of a broader set of Estonian participles that express tense, aspect, and modality without using separate finite verbs.

Usage notes: The past active participle is distinct from the past passive participle and from the verb stem used in other tenses. It conveys agency in the past action and frequently appears in written Estonian to indicate that someone has taught or educated others. In everyday speech, it often occurs in compound tenses or as a descriptive modifier in noun phrases.

Examples:

- Ta on õpetanud kümneid õpilasi. (He has taught dozens of students.)

- Olen õpetanud paljusid lapsi. (I have taught many children.)