"The animal is weak because it has not been eating."
Translation:To zvíře je slabé, protože nejí.
That is how Czech works. "nejí" can mean all of "is not eating right now", "does not eat (ever)", "has not been eating".
A Czech speaker had no problem saying "Nejí už týden." "He hasn't been eating for a week (already)."
Nesnědl is impossible here, it is perfective and is used to rall you ate something (and not just a part of it, the food is now eaten and not available any more).
Nejedl is also possible here, there is no 1:1 mapping of Czech and English tenses.
Often you would distinguish: "Nejí už týden." The person has been ill and has not been able to eat or intentionally has been rejecting food.
"Už týden nejedl." The person didn't have any food to eat, but also it can be the illlness so he has not been able to eat.
You can use both jíst and žrát here.
I've already gathered that Czech can often use the present if there is some other word that indicates the action was past (i.e., už), but it makes sense that if the present is that flexible already it might be more flexible.
Thanks for the tip on the perfective.
Shouldn't the English translation be "The animal is weak because it is not eating" (using the present tense continuous, to translate the imperfective "neji")? Or, vice versa, shouldn't the Czech translation be "To zvíře je slabé, protože nejedl" (taking advantage of the imperfective "jist" to transmit an action perpetuated over time and still incomplete)?
"To zvíře je slabé, protože nejedlo" - is rather "because it did not eat."
"it has not been eating." means pretty much the right thing as I have already explained at this very page before. It means that for since a certain time ago the animal does not eat.
Do note that "is not eating" is accepted here as well.
and more generally, "už" in a negative context usually becomes "no longer/not anymore", except with perfective verbs in the past tense, where it becomes approximately "never" with a shade of "never did get to". hard to say which is anomalous there, czech or english. something deeper in the brain:
- Když jsem se vrátil, už se česky neučil. (When I returned, he was not studying Czech anymore.)
- Už se česky nenaučil. (He never did learn Czech.)
ETA: future tense can go either way.