Questions & Answers about Mi ĵus venkis.
Because the ending -is marks the past tense in Esperanto.
So:
- venki = to win / to defeat
- venkas = wins / is winning
- venkis = won
- venkos = will win
In Mi ĵus venkis, the speaker is talking about something that happened a moment ago, so the past tense is used.
ĵus is an adverb meaning just, just now, or a moment ago.
It tells you that the action happened very recently. In this sentence, it modifies venkis, so the whole idea is I just won or I won just now.
Esperanto usually does not need a separate verb like English have to express this idea.
English often says:
- I have just won
Esperanto normally says:
- Mi ĵus venkis
The adverb ĵus already makes it clear that the action happened very recently, so the simple past tense is enough.