Täheldanud

Täheldanud is an Estonian active past participle formed from the verb täheldama, meaning to notice, perceive or observe. In usage, täheldanud typically functions as part of the perfect aspect when combined with the auxiliary olema, as in olen täheldanud, meaning I have noticed. It can also occur in attributive position as an adjective-like modifier, agreeing with the noun it describes.

Formation and grammar details are typical for Estonian active participles. The form täheldanud corresponds to the past time reference and denotes a completed act of noticing. Like other active past participles, it is used with the auxiliary olla to construct perfect tenses (olen täheldanud, oled täheldanud, on täheldanud, oleme täheldanud, olete täheldanud, on täheldanud). When used attributively, the participle agrees with the noun in case and number, allowing expressions such as täheldanud nähtus (a noticed phenomenon) in appropriate contexts.

Etymology and related forms: täheldanud derives from täheldama, which means to notice or perceive. The noun form täheldus expresses the act or result of perceiving, and related words such as tähelepanu (attention) and tähel rõhutavad forms appear in related constructions. The present active participle form of täheldama is täheldav, used to describe someone or something that notices or is observant, whereas täheldanud marks the completed observation.

Examples:

- Olen täheldanud, et see meetod töötab. (I have noticed that this method works.)

- Ta on täheldanud märkimisväärseid muutusi koolis. (He has noticed significant changes at school.)

Overall, täheldanud is a standard, neutral term in Estonian for indicating that noticing or perception has occurred, and it functions across both verbal tenses and adjectival descriptions.