ɑnand imare the past and future tense words. They go at the beginning of the sentence except for one special case which I'll get to.
The present tense is progressive by default.
mi vɪrɪθmeans "I am running". If you want to communciate that you run in general, but aren't necessarily running now, use the eltense modifier: el mi vɪrɪθ.
This also works with the past and future.
el ɑn mi vɪrɪθ: "I used to run".
el im mi vɪrɪθ: "I will get into running". A bit of a bad example, but the difference from im mi vɪrɪθis that instead of just saying you plan to run, you're communicating that you're going to make it a regular thing.
elthe "vague tense" modifier. ɪris the "close tense" modifier. ɪr ɑn mi vɪrɪθmeans "I just ran", and ɪr im mi vɪrɪθmeans "I'm about to run". ɑŋis the "have done" tense, implying over the normal past that the action is still in effect. Adding this was a recent decision. You can see me talking about it in the comments.
When you use
ɑnor imto go into the past or the future, you stay in the past or future until you use eŋto return to the present. ɑn mi vɪrɪθ, to ɪl tel ɪl verɪθ av mi, kyo mi gu vɪrɪθ. eŋ el mi teku."I ran / was running, then he told me the truth, so I stopped running. Now(adays) I walk."
This is partly for aesthetic reasons. It'd be ugly to have every sentence start with
ɑnwhen telling a story. I also believe it saves more speed than it loses.
If it helps you can think of it like this: "The following sequence of events happened: I run, then he tells me the truth, so I stop running." And you might notice that in English we sometimes do a similar thing when telling a story, especially when it's supposed to be amusing.
This doesn't happen if you place a tense modifier before the verb instead of at the beginning of the sentence.
mi ɑn zu A. kɑ ŋi zu B?. "I did A. Are you doing B?"
If it were
ɑn mi zu A. kɑ ŋi zu B?, it would mean, "I did A. did you do B?"
When using an explicit time-specifying expression, you don't need any tense modifiers. "I run yesterday" is perfectly clear and there's no need to add a syllable to move it to the past.
You can double-use
ɑnand imto get the "had happened" or "will be going to happen" tenses (although the latter isn't very useful). ɑn mi ɑn humi kim ɪl lɪmɵl, kyo nu kei yɪm."I had already drunk all the water, so I didn't have any."
You can also do like this: "
im ɑn mi humi ɪl lɪmɵl" - "I will have drunk the water". You're allowed to combine the tense modifiers in any way that makes sense.
This should go without saying, but just incase, "is going to" should be translated the same way as "will".
Open question: my system for getting the double-past and double-future seems to lead
to extreme ugliness if you want both layers to stick (meaning put both at the start). I don't
think anyone wants to say "