Thank you again, SuStel and charghwI', for your perseverance in helping. I believe that, actually, our opinions don't differ too much. Maybe I've found the source of misunderstanding. When you say in English *Yesterday I ate at 2 pm*, does it mean that at 2 pm you have already eaten? Because in Spanish, when we say *Ayer comí a las 2* (Spanish perfective tense *Pretérito Indefinido*) it actually means you started at 2 pm. The action of eating lasts more than an instant, of course, but due to the perfective aspect this action is nevertheless presented as a completed whole, without referring to its internal flow. Anyway, the important thing is I think I understand now (much better) how aspect works in Klingon, regardless how we say those things in English or Spanish.