Questions & Answers about La kontraŭulo asertis tion.
La is the definite article, meaning the.
So la kontraŭulo means the opponent or the adversary, not just an opponent. Esperanto has only one definite article: la. It does not change for gender, number, or case.
Kontraŭulo is a compound word:
- kontraŭ = against, opposite
- -ul- = a person characterized by something
- -o = noun ending
So kontraŭulo literally means something like a person on the opposite side. In natural English, that becomes opponent, adversary, or rival, depending on context.
This is very typical Esperanto word-building: a root or element + a suffix + a part-of-speech ending.
In Esperanto, verbs always show tense with a fixed ending:
- -as = present
- -is = past
- -os = future
- -us = conditional
- -u = imperative / jussive
- -i = infinitive
So asertis means asserted because -is marks the past tense.
The verb stem here is asert-, from aserti = to assert.