Here's how it works:
* Present Perfect Tense: Used to describe actions that started in the past and continue to the present, or actions that happened in the past with an effect on the present.
* Past Participle: The form of a verb used after auxiliary verbs (like "have" or "has") to create perfect tenses. The past participle of "sing" is "sung".
Examples:
* I have sung in the choir for many years. (action started in the past and continues to the present)
* She has sung a beautiful song. (action happened in the past, and we are aware of the effect now)